Author name code: greve
ADS astronomy entries on 2022-09-14
author:"Greve, Albert" 
------------------------------------------------------------------------  

Title: The EMIR multi-band mm-wave receiver for the IRAM 30-m
    telescope
Authors: Carter, M.; Lazareff, B.; Maier, D.; Chenu, J. -Y.; Fontana,
   A. -L.; Bortolotti, Y.; Boucher, C.; Navarrini, A.; Blanchet, S.;
   Greve, A.; John, D.; Kramer, C.; Morel, F.; Navarro, S.; Peñalver,
   J.; Schuster, K. F.; Thum, C.
Bibcode: 2012A&A...538A..89C
Altcode:
  <BR /> Aims: The prime motivation of this project was to design and
  build a state-of-art mm-wave heterodyne receiver system to enhance
  the observing throughput of the IRAM 30-m radiotelescope. More
  specifically, the requirements were i) state-of-art noise performance
  for spectroscopic observations; ii) simultaneous dual polarization
  and dual-frequency observing; iii) coverage of the atmospheric
  transmission windows from 83 to 360 GHz; iv) compact footprint and
  minimal maintenance. <BR /> Methods: Key elements for low noise
  performance of heterodyne mixers are the superconducting Niobium
  junctions, operating at ≃4 K. These junctions are embedded in
  carefully designed coupling structures; furthermore, since atmospheric
  radiation is a significant contributor to the system noise budget,
  all mixers are either sideband separating or sideband rejecting. To
  achieve low noise, it is also essential to maximize the coupling of the
  receiver to the astronomical source, and to minimize the coupling to
  thermal radiation from the ground-based environment; this is achieved
  through mirror optics that realize a wavelength-independent coupling
  to the telescope. A flexible configuration of mirrors and frequency
  selective surfaces permits various combinations of frequency bands,
  as well as dual-load radiometric calibration. Low noise intermediate
  frequency amplifiers and bias electronics also play an important role in
  the system performance. <BR /> Results: The EMIR receiver in operation
  at the 30 m telescope offers four frequency bands: B1: 83-117 GHz,
  B2: 129-174 GHz, B3: 200-267 GHz, and B4: 260-360 GHz. In each band,
  the two orthogonal polarizations are observed simultaneously. Dual-band
  combinations B1/2 B1/3, and B2/4 are available. Bands 1 and 4 (also 3 as
  of Nov.-2011) feature sideband separation. In dual-band configuration,
  including sideband separation and polarization diplexing, up to eight
  IF channels are delivered to the spectrometers, totaling up to 64 GHz
  of signal bandwidth (of which 32 GHz can be transported and processed
  by spectrometers, status Nov.-2011). The EMIR receiver has been in
  continuous operation for more than two years and has allowed, through
  a qualitative jump in performance, observations not possible before,
  as shown by a few selected examples of astronomical results. <P />This
  article is dedicated to the memory of our colleague Matt who initiated
  and played a key role in this project.

Title: A dynamic thermal model for design and control of an
    800-element open-air radio telescope
Authors: Bremer, Michael; Greve, Albert
Bibcode: 2011SPIE.8336E..0UB
Altcode: 2011SPIE.8336E..29B
  In earlier work we have described the thermal modelling for design and
  control of a fully insulated, and sometimes ventilated, high precision
  radio telescope. For such an insulated telescope the modelling of the
  time-variable dynamic influence of the thermal environment (air, sky
  and ground radiation, insolation) is relatively simple. The modelling
  becomes however quite complex for an open-air radio telescope where
  each individual member of the reflector backup structure (BUS) and
  the support structure (fork or yoke) is exposed under a different
  and time-dependent aspect angle to the thermal environment, which
  applies in particular to solar radiation. We present a time-dependent
  800-element thermal model of an open-air telescope. Using the IRAM
  30-m radio telescope as the basic mechanical structure, we explain
  how the temperature induced, real-time pointing and reflector surface
  deformations can be derived when using as input the day of the year,
  the thermal environment, and the geographic position of the telescope
  and its changing pointing direction. Thermal modelling and results
  similar to those reported here can be used for radio telescope design
  and real-time control of pointing and surface adjustment of a telescope
  with active panels.

Title: The apparent "reversed" motion of gas and stars in M 82
Authors: Greve, A.
Bibcode: 2011A&A...529A..51G
Altcode:
  We summarize earlier and unpublished long-slit spectroscopic
  measurements of radial velocities of ionized gas and stars along
  and parallel to M 82's major axis to a radial distance of ~±2.5 kpc
  (~±140'') from the center. In the position-velocity diagram, these
  measurements indicate a velocity reversal of ~100 km s<SUP>-1</SUP>
  of gas and/or stars at ~±1.0 kpc (~±50-70'') on either side of
  the center, outside the bar. Although seen in earlier observations,
  and perhaps neglected because they were assumed to be only an effect
  of heavy local extinction, the positional symmetry of the velocity
  reversal with respect to the center of M 82, as well as the absence
  of the reversal in the motion of stars seen in the near-IR Ca ii
  absorption lines, points to another origin. M 82's two-armed spiral,
  as outlined by Mayya et al. (2005, ApJ, 628, L33), may explain a
  part of the velocity reversal, although this interpretation leaves
  inconsistencies so that other explanations must also be investigated. A
  simple, conclusive explanation of the velocity reversal has not yet been
  found. While restricted observationally in radial distance to ~120''
  (2 kpc), the near-IR stellar Ca ii absorption lines, which do not show
  the velocity reversal, indicate a flat radial velocity curve of the
  stellar disk that remained after the encounter with M 81.

Title: Extinction A<SUB>V</SUB>, R towards emission nebulae derived
    from common upper level Paschen-Balmer hydrogen lines
Authors: Greve, A.
Bibcode: 2010A&A...518A..62G
Altcode:
  The reddening in and around emission nebulae is characterized by the
  extinction A<SUB>V</SUB> and the ratio R of the absolute-to-selective
  absorption. Both are usually derived from the photometry of a single
  star or cluster stars that are associated with an emission nebula. Using
  the parameterized reddening relation published by Cardelli et al. (1989,
  ApJ, 345, 245), we show that A<SUB>V</SUB> and R can be derived with
  good precision from the observation of a set of common upper level
  Paschen-Balmer hydrogen line ratios. The use of common upper level line
  ratios has the advantage of being nearly independent of the excitation
  condition of the nebula (n<SUB>e</SUB>, T<SUB>e</SUB>). The line ratio
  method can be applied in regions where no stars are available for
  photometry. <P />Partially based on observations made at ESO, La Silla.

Title: The Beam Pattern of Reflector Antennas With Buckled Panels
Authors: Greve, A.; Morris, D.; Penalver, J.; Thum, C.; Bremer, M.
Bibcode: 2010ITAP...58..959G
Altcode:
  On high precision reflector telescopes the transient thermal panel
  buckling can have an effective rms-value comparable to the errors
  in the adjustment of the reflector panels. Under this condition,
  high signal-to-noise radio holography of high spatial resolution
  can reveal the characteristic signature of panel buckling in the
  beam pattern and can map the surface deformation of the buckling,
  while lower signal-to-noise Moon limb scans may see the buckling
  only under favorable conditions. Detailed diffraction calculations,
  and some observations, indicate (1) that the panel buckling produces
  diffraction rings and/or diffraction spokes, (2) that panel buckling
  in azimuthal direction may have a smaller degrading effect than panel
  buckling in radial direction because for azimuthal buckling the energy
  is spread more uniformly over a large solid angle, and (3) that the
  coverage of the reflector aperture with buckled panels determines the
  multiplicity of the diffraction rings and/or diffraction spokes.

Title: Thermal Design and Thermal Behaviour of Radio Telescopes and
    their Enclosures
Authors: Greve, Albert; Bremer, Michael
Bibcode: 2010ASSL..364.....G
Altcode:
  No abstract at ADS

Title: Performance Improvement of a Flexible Telescope Through
    Metrology and Active Control
Authors: Greve, Albert; Karcher, Hans Jurgen
Bibcode: 2009IEEEP..97.1412G
Altcode:
  A radio telescope is a flexible structure under the influence of
  gravity, temperature, and wind. Even after all passive means of
  telescope construction have been applied, the residual structural
  deformations of a high precision telescope may still lead to focus,
  pointing, and path-length errors and a loss in gain that exceed
  the performance specifications. Gravity-induced deformations can be
  calculated and corrected with high precision. While the time-variable
  nature of temperature- and wind-induced deformations can only partially
  be explored in numerical simulations, their control requires the input
  from metrology. Corrections can be made through the telescope control
  system but also, to some extent, through deformable mirror surfaces. The
  progress in metrology and the correction of certain telescope errors
  are described.

Title: The brightness temperature of Mercury at mm-wavelengths
Authors: Greve, A.; Thum, C.; Moreno, R.; Yan, N.
Bibcode: 2009A&A...495..639G
Altcode:
  We present observations of Mercury made with the IRAM 30-m telescope
  at 3, 2 and 1.3 mm wavelength (90, 150 and 230 GHz) during the years
  1985-2005; we derive from these data the disk-averaged brightness
  temperatures. The observations at 3 mm combined with those by Epstein
  &amp; Andrew allow a separation of the data into 40° wide longitude
  intervals and by this an investigation of the disk-averaged brightness
  temperature with Mercury's longitude. From the new mm-wavelength data,
  and data taken from the literature, we derive the disk-averaged
  brightness temperature as a function of wavelength. On Mercury's
  night side a significant decrease in brightness temperature occurs
  towards shorter wavelengths. We use the three surface models (A,B,C)
  discussed by Mitchell &amp; de Pater and calculate for the cool
  and hot surface region the corrresponding diurnal variation of the
  disk-averaged brightness temperature at 90 GHz. For the same models we
  calculate the variation of the disk-averaged brightness temperature
  with wavelength between 1.3 mm and 37 mm, on Mercury's midnight side
  and noon side. Although the scatter in the observations is large,
  there seems to be a marginally better agreement with model B and A.

Title: A Global 86 GHz VLBI Survey of Compact Radio Sources
Authors: Lee, Sang-Sung; Lobanov, Andrei P.; Krichbaum, Thomas P.;
   Witzel, Arno; Zensus, Anton; Bremer, Michael; Greve, Albert; Grewing,
   Michael
Bibcode: 2008AJ....136..159L
Altcode: 2008arXiv0803.4035L
  We present results from a large 86 GHz global very long baseline
  interferometry (VLBI) survey of compact radio sources. The main goal of
  the survey is to increase by factors of 3-5 the total number of objects
  accessible for future 3 mm VLBI imaging. The survey observations reach
  a baseline sensitivity of 0.1 Jy and an image sensitivity of better
  than 10 mJy beam<SUP>-1</SUP>. A total of 127 compact radio sources
  have been observed. The observations have yielded images for 109
  sources, extending the database of the sources imaged at 86 GHz with
  VLBI observation by a factor of 5, and only six sources have not been
  detected. The remaining 12 objects have been detected but could not be
  imaged due to insufficient closure phase information. Radio galaxies are
  less compact than quasars and BL Lac objects on the sub-milliarcsecond
  scale. The flux densities and sizes of the core and jet components
  of all imaged sources have been estimated using Gaussian model
  fitting. From these measurements, brightness temperatures have been
  calculated, taking into account the resolution limits of the data. The
  cores of 70% of the imaged sources are resolved. The core brightness
  temperatures of the sources peak at ~10<SUP>11</SUP> K and only 1%
  have brightness temperatures higher than 10<SUP>12</SUP> K. The cores
  of intraday variable (IDV) sources are smaller in angular size than
  those of non-IDV sources, and so yield higher brightness temperatures.

Title: Mechanical Measurements of the ALMA Prototype Antennas
Authors: Greve, Albert; Mangum, Jeff
Bibcode: 2008IAPM...50b..66G
Altcode: 2007arXiv0710.5629G
  The specifications of the Atacama Large Millimeter Array (ALMA)
  have placed stringent requirements on the mechanical performance of
  its antennas. As part of the evaluation process of the VertexRSI and
  Alcatel EIE Consortium (AEC) ALMA prototype antennas, measurements
  of the path length, thermal, and azimuth bearing performance were
  made under a variety of weather conditions and observing modes. The
  results of mechanical measurements, reported here, are compared to
  the antenna specifications.

Title: Long-term observations of Uranus and Neptune at 90 GHz with
    the IRAM 30 m telescope. (1985-2005)
Authors: Kramer, C.; Moreno, R.; Greve, A.
Bibcode: 2008A&A...482..359K
Altcode: 2008arXiv0801.4452K
  Context: The planets Uranus and Neptune with small apparent diameters
  are primary calibration standards. <BR />Aims: We investigate their
  variability at ~90 GHz using archived data taken with the IRAM 30 m
  telescope during the 20 year period 1985 to 2005. <BR />Methods: We
  calibrate the planetary observations against non-variable secondary
  standards (NGC 7027, NGC 7538, W3OH, K3-50A) observed almost
  simultaneously. <BR />Results: Between 1985 and 2005, the viewing
  angle of Uranus changed from south-pole to equatorial. We find that
  the disk brightness temperature declines by almost 10% (~2σ) over
  this time span indicating that the south-pole region is significantly
  brighter than average. Our finding is consistent with recent long-term
  radio observations at 8.6 GHz. Both data sets show a rapid decrease of
  the Uranus brightness temperature during 1993, indicating a temporal,
  planetary scale change. We do not find indications for a variation of
  Neptune's brightness temperature at the 8% level. <BR />Conclusions:
  If Uranus is to be used as a calibration source, and if accuracies
  better than 10% are required, the Uranus sub-earth point latitude
  needs to be taken into account.

Title: Towards the Event Horizon: High Resolution VLBI Imaging of
    Nuclei of Active Galaxies
Authors: Krichbaum, T. P.; Graham, D. A.; Witzel, A.; Zensus, J. A.;
   Greve, A.; Grewing, M.; Bremer, M.; Doeleman, S.; Phillips, R. B.;
   Rogers, A. E. E.; Fagg, H.; Strittmatter, P.; Ziurys, L.
Bibcode: 2007ecf..book..189K
Altcode: 2006astro.ph..7077K
  Very Long Baseline Interferometry at millimetre wavelengths (mm-VLBI)
  allows to image compact galactic and extragalactic radio sources with
  microarcsecond resolution, unreachable by other astronomical observing
  techniques. Future global VLBI at millimetre wavelengths therefore
  should allow to map,with a spatial resolution of only a few to a few
  ten gravitational radii, the direct vicinity of the Super Massive
  Black Holes (SMBH) located in the centres of nearby galaxies. With
  the reduced intrinsic self-absorption at short wavelengths, mm- VLBI
  opens a direct view onto the often jet-producing "central engine".

Title: Characteristics and Performance of the North American ALMA
    Prototype Antenna
Authors: Mangum, J. G.; Baars, J. W. M.; Greve, A.; Lucas, R.; Snel,
   R.; Wallace, P.
Bibcode: 2006ASPC..356..253M
Altcode:
  The submillimeter antennas of the Atacama Large Millimeter Array
  (ALMA) have specifications that are beyond the current state of
  the art in accurate reflector antenna technology. Considering that
  as many as 64 of these antennas will eventually be needed, the ALMA
  partners AUI/NRAO and ESO each agreed to acquire a prototype antenna,
  and subject these to an extensive evaluation program. In this paper we
  summarize the performance of the ALMA North American prototype antenna.

Title: NGC 2146's starburst region and extended structure
Authors: Greve, A.; Neininger, N.; Sievers, A.; Tarchi, A.
Bibcode: 2006A&A...459..441G
Altcode:
  We present mm-wavelength and optical observations of the starburst
  region in NGC 2146. This region of ~4 kpc diameter contains a
  well-ordered distribution of stars, gas, and dust, and a well-ordered
  rotation. The possible anomalies found in our observation are a warped
  CO distribution and an increase in the CO line width at the NW edge
  of the starburst region. The investigation of a possible encounter or
  merger origin of the starburst may therefore have to concentrate on the
  distorted outer structure of the galaxy. There are three large-scale
  features of ~20 kpc extent, two of which give the impression of being
  stellar sub-systems. The third feature is an incomplete and expanding
  ring of H ii regions and stars, apparently indicating an event that
  occurred some 300 Myr ago.

Title: Evaluation of the ALMA Prototype Antennas
Authors: Mangum, Jeffrey G.; Baars, Jacob W. M.; Greve, Albert; Lucas,
   Robert; Snel, Ralph C.; Wallace, Patrick; Holdaway, Mark
Bibcode: 2006PASP..118.1257M
Altcode: 2006PASP..118.1260M; 2006astro.ph..9329M
  The ALMA (Atacama Large Millimeter Array) North American and European
  prototype antennas have been evaluated by a variety of measurement
  systems to quantify the major performance specifications. Near-field
  holography was used to set the reflector surfaces to 17 μm
  rms. Pointing and fast-switching performance was determined with an
  optical telescope and by millimeter-wavelength radiometry, yielding 2"
  absolute and 0.6" offset pointing accuracies. Path-length stability
  was measured to be &lt;~20 μm over 10 minute time periods using
  optical measurement devices. Dynamical performance was studied with a
  set of accelerometers, providing data on wind-induced tracking errors
  and structural deformation. Considering all measurements made during
  this evaluation, both prototype antennas meet the major ALMA antenna
  performance specifications. <P />The performance results presented
  in this publication were part of a comprehensive technical evaluation
  process used to evaluate the ALMA prototype antennas, which concluded
  in 2005 April.

Title: Calculated thermal behavior of ventilated high precision
    radio telescopes
Authors: Greve, A.; Bremer, M.
Bibcode: 2006IAPM...48....9G
Altcode: 2006IAPM...48....9.
  Radio telescopes that operate at millimeter and sub-millimeter
  wavelengths need a reflector-surface precision of a few tens of
  microns and a pointing accuracy of a few arcseconds. When built
  in a conventional way from steel and aluminum, as in the case of
  larger-diameter telescopes, thermal control must be applied to reduce
  temperature-induced deformations, in particular of the reflector backup
  structure. We illustrate that it is possible to make model calculations
  - for instance, during the design phase - that simulate the thermal
  behavior and the operation of a telescope when servo-loop-controlled
  ventilation or climatization (air-conditioned ventilation) of the backup
  structure is applied. We explain the technique of model calculations,
  and present as an example the calculated thermal behavior of a
  ventilated 64-m-diameter telescope and of the climatized 30-m IRAM
  telescope. It is explained that the thermal control of a telescope
  mount is less demanding if frequent pointing corrections can be made.

Title: APEX: the Atacama Pathfinder EXperiment
Authors: Güsten, R.; Booth, R. S.; Cesarsky, C.; Menten, K. M.;
   Agurto, C.; Anciaux, M.; Azagra, F.; Belitsky, V.; Belloche, A.;
   Bergman, P.; De Breuck, C.; Comito, C.; Dumke, M.; Duran, C.; Esch,
   W.; Fluxa, J.; Greve, A.; Hafok, H.; Häupl, W.; Helldner, L.;
   Henseler, A.; Heyminck, S.; Johansson, L. E.; Kasemann, C.; Klein,
   B.; Korn, A.; Kreysa, E.; Kurz, R.; Lapkin, I.; Leurini, S.; Lis, D.;
   Lundgren, A.; Mac-Auliffe, F.; Martinez, M.; Melnick, J.; Morris,
   D.; Muders, D.; Nyman, L. A.; Olberg, M.; Olivares, R.; Pantaleev,
   M.; Patel, N.; Pausch, K.; Philipp, S. D.; Philipps, S.; Sridharan,
   T. K.; Polehampton, E.; Reveret, V.; Risacher, C.; Roa, M.; Sauer, P.;
   Schilke, P.; Santana, J.; Schneider, G.; Sepulveda, J.; Siringo, G.;
   Spyromilio, J.; Stenvers, K. -H.; van der Tak, F.; Torres, D.; Vanzi,
   L.; Vassilev, V.; Weiss, A.; Willmeroth, K.; Wunsch, A.; Wyrowski, F.
Bibcode: 2006SPIE.6267E..14G
Altcode:
  APEX, the Atacama Pathfinder Experiment, has been successfully
  commissioned and is in operation now. This novel submillimeter telescope
  is located at 5107 m altitude on Llano de Chajnantor in the Chilean High
  Andes, on what is considered one of the world's outstanding sites for
  submillimeter astronomy. The primary reflector with 12 m diameter has
  been carefully adjusted by means of holography. Its surface smoothness
  of 17-18 μm makes APEX suitable for observations up to 200 μm,
  through all atmospheric submm windows accessible from the ground.

Title: A multi-layered thermal model of backup structures for
    mm-wavelength radio telescopes
Authors: Greve, A.; Smith, D. R.; Bremer, M.
Bibcode: 2006SPIE.6271E..0KG
Altcode: 2006SPIE.6271E..20G
  An unfavourable influence that degrades the performance of any
  millimeter wavelength radio telescope is the deformation of the
  reflector surface due to temperature differences in the supporting
  backup structure. To avoid, or at least reduce this influence, the
  backup structures are typically protected by a rear side cladding,
  insulation at the panel inner side, and ventilation or climatization
  of the air inside the backup structure. During the design of a
  mm-wavelength telescope, the layout of a thermal protection system is
  made, based on experience gained on other telescopes, and on thermal
  model calculations of the complete backup structure. The available
  thermal programs allow today the construction of a multi-layered
  backup structure model, consisting of the backup structure tube
  network, without and with ventilation/climatization, the panels,
  insulation behind the panels, and the rear side cladding. We provide a
  guideline for the construction of such a multi-layered thermal model,
  and demonstrate that realistic temperature gradients across and through
  a backup structure can be calculated. These gradients can be used in a
  finite element model to calculate the reflector surface deformations,
  which can be used in a diffraction program to calculate the radio
  beam pattern.

Title: A global 86 GHz VLBI survey of compact radio sources
Authors: Lee, Sang-Sung; Lobanov, A. P.; Krichbaum, T. P.; Witzel,
   A.; Zensus, A.; Bremer, M.; Greve, A.; Grewing, M.
Bibcode: 2006evn..confE...4L
Altcode: 2006PoS....36E...4L
  We present results from a large global VLBI survey of compact radio
  sources at 86 GHz begun in October 2001. The main goal of the survey
  was to increase the total number of objects accessible for future
  3-mm VLBI imaging by factors of 3 ~ 5. The survey data attained the
  baseline sensitivity of 0.1 Jy, and image sensitivity of better than
  10 mJy/beam. To date, a total of 127 compact radio sources have been
  observed. The observations have yielded images for 109 sources, and
  only 6 sources have not been detected. Flux densities and sizes of
  core and jet components of all detected sources have been measured
  using Gaussian model fitting. From these measurements, brightness
  temperatures have been estimated, taking into account resolution
  limits of the data. Here, we compare the brightness temperatures of
  the cores and secondary jet components with similar estimates obtained
  from surveys at longer wavelengths (e.g. 15 GHz). This approach can
  be used to study the phenomena related to mechanisms of initial jet
  acceleration (accelerating or decelerating sub-pc jets?) and jet
  composition (electron-positron or electron-proton plasma?).

Title: Extending VLBI to 2mm and 1mm Wavelengths
Authors: Doeleman, S. S.; Phillips, R. B.; Rogers, A. E. E.; Attridge,
   J. M.; Titus, M. A.; Smythe, D. L.; Cappallo, R. J.; Buretta, T. A.;
   Whitney, A. R.; Krichbaum, T.; Graham, D. A.; Alef, W.; Polatidis,
   A.; Bach, U.; Kraus, A.; Witzel, A.; Wilson, T.; Zensus, J. A.; Greve,
   A.; Grewing, M.; Freund, R.; Ziurys, L.; Fagg, H.; Strittmatter, P.
Bibcode: 2005ASPC..340..605D
Altcode:
  Technical VLBI experiments have been carried out at wavelengths shorter
  than 3mm, yielding the highest angular resolutions ever attained in any
  waveband. Long baseline detections of AGN at 129GHz, 147GHz, and 230GHz
  have fringe spacings (λ/D) of 56, 49, and 34μas respectively. We
  also present the first 129GHz VLBI map of the SiO masers associated
  with the evolved star VY CMa.

Title: Improvement of the IRAM 30-m Telescope From Temperature
    Measurements and Finite-Element Calculations
Authors: Greve, A.; Bremer, M.; Penalver, J.; Raffin, P.; Morris, D.
Bibcode: 2005ITAP...53..851G
Altcode:
  Millimeter wavelength radio telescopes built in a conventional way from
  steel and aluminum require elaborate thermal control to guarantee small
  structural deformations and good observational performance. We describe
  the temperature monitoring system of the Institut de Radioastronomie
  Millimetrique 30-m telescope and the use of temperature measurements
  in finite-element calculations of structural deformations. These
  calculations reproduce with good precision the measured thermal
  deformations of the telescope and allow the investigation and
  localization of thermally important elements in the telescope
  structure. The data are used for calculation of temperature induced
  main reflector surface deformations and of the associated actual beam
  pattern, and for prediction and real-time correction of the focus. The
  pointing cannot be fully predicted since the available finite-element
  model does not include the Nasmyth focus cabin (and the concrete
  pedestal). The long-term investigation of the telescope's thermal
  behavior led to an improvement of the thermal control system and to
  a better performance of the telescope.

Title: Neutral Hydrogen Absorption at the Center of NGC 2146
Authors: Tarchi, A.; Greve, A.; Peck, A.; Neininger, N.; Wills, K.;
   Pedlar, A.; Klein, U.
Bibcode: 2004ASPC..320..112T
Altcode:
  No abstract at ADS

Title: A 230 GHz heterodyne receiver array for the IRAM 30 m telescope
Authors: Schuster, K. -F.; Boucher, C.; Brunswig, W.; Carter, M.;
   Chenu, J. -Y.; Foullieux, B.; Greve, A.; John, D.; Lazareff, B.;
   Navarro, S.; Perrigouard, A.; Pollet, J. -L.; Sievers, A.; Thum, C.;
   Wiesemeyer, H.
Bibcode: 2004A&A...423.1171S
Altcode:
  We describe the technical concept, properties, and performance of HERA
  (HEterodyne Receiver Array) at the IRAM 30 m telescope. HERA is a
  multibeam, waveguide SIS receiver that greatly improves mapping speed
  in various observing modes and also provides possibilities for new
  high-sensitivity observing of small sources. Future extensions with a
  second polarization module will permit spectro-polarimetry. We present
  some examples of astronomical maps with HERA.

Title: Neutral hydrogen absorption at the centre of NGC 2146
Authors: Tarchi, A.; Greve, A.; Peck, A. B.; Neininger, N.; Wills,
   K. A.; Pedlar, A.; Klein, U.
Bibcode: 2004MNRAS.351..339T
Altcode: 2003astro.ph..9447T
  We present 1.4-GHz HI absorption line observations towards the
  starburst in NGC 2146, made with the Very Large Array and the
  Multi-Element Radio-Linked Interferometer Network. The HI gas has
  a rotating disc/ring structure with column densities between 6 and
  18 × 10<SUP>21</SUP> atom cm<SUP>-2</SUP>. The HI absorption has a
  uniform spatial and velocity distribution, and does not reveal any
  anomalous material concentration or velocity in the central region of
  the galaxy which might indicate an encounter with another galaxy or a
  far-evolved merger. We conclude that the signs of an encounter causing
  the starburst should be searched for in the outer regions of the galaxy.

Title: HI absorption at the center of NGC2146
Authors: Tarchi, A.; Greve, A.; Peck, A. B.; Neininger, N.; Wills,
   K. A.; Pedlar, A.; Klein, U.
Bibcode: 2004astro.ph..3127T
Altcode:
  We present 1.4 GHz HI absorption line observations towards the starburst
  in NGC2146, made with the VLA and MERLIN. The HI gas has a rotating
  disk/ring structure with column densities between 6 and 18 x 10(21)
  atoms cm(-2). The HI absorption has a uniform spatial and velocity
  distribution, and does not reveal any anomalous material concentration
  or velocity in the central region of the galaxy which might indicate
  an encounter with another galaxy or a far-evolved merger. We conclude
  that the signs of an encounter causing the starburst should be searched
  for in the outer regions of the galaxy.

Title: The rotating visible outflow in M 82
Authors: Greve, A.
Bibcode: 2004A&A...416...67G
Altcode:
  M 82's minor axis outflow is seen at visible wavelengths as more or
  less regular hollow cones on both sides of the galactic disk. The
  outflowing material is expected to entrain the rotation, or part of
  the rotation, of the disk where the outflow originates. From the
  conservation of angular momentum it is furthermore expected that
  the outflowing material continues to rotate at large distances from
  the disk, although probably with smaller velocity because of radial
  divergence of the cones. We provide evidence of this kinematic picture
  from long-slit spectra of the cone wall H<SUB>\alpha</SUB>, [NII]
  and [SII] emission lines taken at ±20'' (±300 pc) and ∼±40''
  (∼±600 pc) distance from the center and parallel to the minor axis,
  from data extracted from the literature, and from a cone model fit
  of the data. The angular momentum which is entrained in the outflow
  and eventually dissipated is a small fraction of the total angular
  momentum associated with the stars and gas in the central part of the
  disk. We compare our observation of the visible outflow with the outflow
  of dragged-out material investigated in mm-wavelength CO by other
  observers. It seems that the material observed at visible wavelengths
  is confined to narrow cones, and blows out at velocities larger than
  the escape velocity of the galaxy. The dragged-out material moves at
  slower velocities and on wider cones, and may fall back into the galaxy.

Title: Towards the Event Horizon - The Vicinity of AGN at
    Micro-Arcsecond Resolution
Authors: Krichbaum, T. P.; Graham, D. A.; Alef, W.; Kraus, A.; Sohn,
   B. W.; Bach, U.; Polatidis, A.; Witzel, A.; Zensus, J. A.; Bremer,
   M.; Greve, A.; Grewing, M.; Doeleman, S.; Phillips, R. B.; Rogers,
   A. E. E.; Fagg, H.; Strittmatter, P.; Ziurys, L.; Conway, J.; Booth,
   R. S.; Urpo, S.
Bibcode: 2004evn..conf...15K
Altcode: 2004astro.ph.11487K
  We summarize the present status of VLBI experiments at 3 mm (86 GHz),
  2 mm (129-150 GHz) and 1.3 mm (215-230 GHz). We present and discuss
  a new 3 mm VLBI map of M 87, which has a spatial resolution of only
  ∼ 20 Schwarzschild radii. We discuss recent results for Sgr A*
  and argue in favor of new observations within an extended European
  mm-VLBI network, in order to search for variability. We discuss the
  possibilities to image the `event horizon' of a super-massive black
  hole at wavelengths &lt; 2 mm, and conclude that the addition of
  large and sensitive millimetre telescopes such as CARMA, the SMA,
  the LMT and ALMA will be crucial for this. (astro-ph/0411487)

Title: Millimetre-VLBI Monitoring of AGN with Sub-milliarcsecond
    Resolution
Authors: Pagels, A.; Krichbaum, T. P.; Graham, D. A.; Alef, W.;
   Kadler, M.; Kraus, A.; Klare, A.; Witzel, J. A.; Zensus, A.; Greve,
   A.; Grewing, M.; Booth, R.; Conway, J.
Bibcode: 2004evn..conf....7P
Altcode: 2004astro.ph..9328P
  Global millimetre VLBI allows detailed studies of the most central jet
  regions of AGN with unprecedent spatial resolution of a few 100--1000
  Schwartzschild radii to be made. Study of these regions will help to
  answer the question how the highly relativistic AGN jets are launched
  and collimated. Since the early 1990s, bright mm-sources have been
  observed with global 3 mm VLBI. Here we present new images from
  an ongoing systematic analysis of the available observations. In
  particular, we focus on the structure and structural evolution
  of the best observed AGN jets, taking 3C 454.3 as a characteristic
  example. This core-dominated and highly variable quasar shows a complex
  morphology with individual jet components accelerating superluminally
  towards the outer structure. We briefly discuss the X-ray properties
  of 3C 454.3 and present its radio- to X-ray large-scale brightness
  distribution. (astro-ph/0409328)

Title: Millimeter VLBI and Variability in AGN Jets
Authors: Krichbaum, T. P.; Graham, D. A.; Witzel, A.; Zensus, J. A.;
   Greve, A.; Ungerechts, H.; Grewing, M.
Bibcode: 2003ASPC..299..249K
Altcode: 2003astro.ph..8043K; 2003heba.conf..249K
  Millimeter-VLBI images probe as deep as never before the nuclei
  of AGN. VLBI at 147 GHz yields transatlantic fringes for the first
  time. Now we can begin to study the relation between jet kinematics
  and spectral activity with a few ten micro-arcsecond resolution.

Title: 2mm Wavelength VLBI: SiO Masers in the Envelope of VYCMa
Authors: Doeleman, S. S.; Phillips, R. B.; Rogers, A. E. E.; Attridge,
   J. M.; Titus, M. A.; Smythe, D. L.; Cappallo, R. J.; Buretta, T. A.;
   Whitney, A. R.; Krichbaum, T.; Graham, D. A.; Alef, W.; Polatidis,
   A.; Bach, U.; Witzel, A.; Zensus, J. A.; Greve, A.; Grewing, M.;
   Freund, R.; Strittmatter, P.; Ziurys, L.; Wilson, T.; Fagg, H.
Bibcode: 2002AAS...20111508D
Altcode: 2002BAAS...34R1291D
  In April 2002 an array of antennas operating at 129GHz successfully
  detected VLBI fringes on both continuum AGN and SiO spectral line
  sources. The 129GHz fringes on maser sources represent the highest
  frequency spectral line VLBI detections to date. The AGN 3C279 was
  detected on long baselines at both 129GHz (and at 147GHz) yielding
  fringe spacings of 50-56 micro arc seconds, an angular resolution
  record. The array consisted of the Kitt Peak 12m antenna and the
  Heinrich Hertz 10m Telescope (HHT), both operatedby the Arizona Radio
  Observatory, and the IRAM 30m dish on Pico Veleta (Spain). At 129GHz,
  a number of evolved stars and several young stellar objects exhibit
  strong SiO maser emission in the v=1 J=3-2 transition. We present
  maps of the v=1 J=3-2 maser emission towards the hypergiant VYCMa and
  discuss the relation of the maser features to the optical asymmetric
  nebula surrounding the star. Future high frequency VLBI using these
  telescopes will include continuum observations of the radio source at
  the Galactic Center, SgrA*, and higher frequency maser lines including
  HCN and methanol.

Title: 147 GHz VLBI observations: Detection of 3C 273 and 3C 279 on
    the 3100 km baseline Metsähovi - Pico Veleta
Authors: Greve, A.; Könönen, P.; Graham, D. A.; Wiik, K.; Krichbaum,
   T. P.; Conway, J.; Rantakyrö, F.; Urpo, S.; Grewing, M.; Booth,
   R. S.; Zensus, J. A.; John, D.; Navarro, S.; Mujunen, A.; Ritakari,
   J.; Peltonen, J.; Sjöman, P.; Oinaskallio, E.; Berton, M.
Bibcode: 2002A&A...390L..19G
Altcode:
  We report a successful VLBI observation at 147 GHz (2.1 mm) on the 3
  100 km long baseline between the telescopes at Metsähovi (Finland)
  and Pico Veleta (Spain). The sources 3C 273B and 3C 279 were detected
  with a SNR of ~ 10. For these sources we estimate that 25-30% of the
  total flux is detectable as correlated flux on the 3 100 km baseline,
  which gives at 147 GHz a lower limit of the brightness temperature of
  the inner VLBI jet region of ~ 1x10<SUP>10</SUP> K.

Title: 1st Global mm-VLBI at 512 Mbits
Authors: Graham, D. A.; Alef, W.; Krichbaum, T. P.; Kraus, A.; Greve,
   A.; Conway, J. E.; Attridge, J. M.; Buretta, T. A.; Shute, P. A.;
   Titus, M. A.
Bibcode: 2002evn..conf...67G
Altcode:
  At the end of the 86 GHz CMVA session in October 2001, a first mm-VLBI
  observation was conducted which used a recording bit-rate of 512 Mbits/s
  utilizing the Mk IV recording system. The four radio telescopes involved
  were Onsala, Effelsberg, Pico Veleta, and Haystack. In 20 hours of
  observing time 8 sources --- 1156+295, 1633+382, 1803+784, 3C273,
  3C274, 3C345, 3C454.3, BL Lac --- were observed in a snapshot-like
  mode. All sources could be detected thanks to the 40% sensitivity
  increase obtained by doubling the usual recording rate, and simple
  maps could be made.

Title: 2mm Wavelength VLBI of SiO Masers and AGN
Authors: Doeleman, S. S.; Phillips, R. B.; Rogers, A. E. E.; Attridge,
   J. M.; Titus, M.; Smythe, D.; Cappallo, R.; Buretta, T.; Whitney,
   A. R.; Krichbaum, T. P.; Graham, D. A.; Alef, W.; Polatidis, A. G.;
   Bach, U.; Witzel, A.; Zensus, J. A.; Greve, A.; Grewing, M.; Freund,
   R.; Strittmatter, P.; Ziurys, L.; Wilson, T. L.; Fagg, H.; Gay, G.
Bibcode: 2002evn..conf..223D
Altcode: 2002astro.ph..7072D
  In April 2002 an array of antennas operating at 129GHz successfully
  detected VLBI fringes on both continuum AGN and SiO spectral line
  sources. The 129GHz fringes represent the highest frequency spectral
  line VLBI detections to date. The array consisted of the University of
  Arizona Kitt Peak 12m antenna, the Sub Millimeter Telescope Observatory
  10m (HHT), and the IRAM 30m dish on Pico Veleta. These observations
  are the first fringes at any frequency at the SMTO and we discuss the
  technical challenges involved. <P />At 129GHz, a number of evolved stars
  and several young stellar objects exhibit strong SiO maser emission in
  the v = 1 J = 3-2 transition. Preliminary cross power spectra of VYCMa
  on the HHT-Kitt Peak baseline (∼190km) are consistent with multiple
  spatially separate maser spots associated with the star. We discuss
  phase mapping this emission and the implications for constraining the
  SiO maser pumping mechanisms and circumstellar dynamics around these
  objects. Future observations will include continuum observations of
  the radio source at the Galactic Center, SgrA*, and higher frequency
  maser lines including HCN and methanol.

Title: VLBI observations at 147 GHz: first detection of transatlantic
    fringes in bright AGN
Authors: Krichbaum, T. P.; Graham, D. A.; Alef, W.; Polatidis, A. G.;
   Bach, U.; Witzel, A.; Zensus, J. A.; Greve, A.; Grewing, M.; Doeleman,
   S. S.; Phillips, R. M.; Rogers, A. E. E.; Titus, M. A.; Fagg, H.;
   Strittmatter, P.; Wilson, T. L.; Ziurys, L.; Freund, R.; Peltonen,
   P. K. J.; Urpo, S.; Rantakyr, F.; Conway, J. E.; Booth, R. S.
Bibcode: 2002evn..conf..125K
Altcode: 2002astro.ph..7022K
  At 147 GHz (2 mm wavelength), we detected three prominent AGN (NRAO
  150, 3C 279, 1633+382) with Very Long Baseline Interferometry (VLBI)
  with an angular resolution of only ∼18 micro-arcseconds. This is a
  new world record in radio interferometry and astronomical imaging and
  opens fascinating future possibilities to directly image and study
  the innermost regions in quasars and other active galactic nuclei.

Title: A search for radio supernovae and supernova remnants in the
    region of NGC 1569's super star clusters
Authors: Greve, A.; Tarchi, A.; Hüttemeister, S.; de Grijs, R.;
   van der Hulst, J. M.; Garrington, S. T.; Neininger, N.
Bibcode: 2002A&A...381..825G
Altcode: 2001astro.ph.11221G
  We have used MERLIN, at 1.4 and 5 GHz, to search for radio supernovae
  (RSNe) and supernova remnants (SNRs) in the unobscured irregular dwarf
  galaxy NGC 1569, and in particular in the region of its super star
  clusters (SSCs) A and B. Throughout NGC 1569 we find some 5 RSNe and
  SNRs but the SSCs and their immediate surroundings are largely devoid
  of non-thermal radio sources. Even though many massive stars in the
  SSCs are expected to have exploded already, when compared with M 82
  and its many SSCs the absence of RSNe and SNRs in and near A and B
  may seem plausible on statistical arguments. The absence of RSNe and
  SNRs in and near A and B may, however, also be due to a violent and
  turbulent outflow of stellar winds and supernova ejected material,
  which does not provide a quiescent environment for the development of
  SNRs within and near the SSCs.

Title: M 82's stellar bar
Authors: Greve, A.; Wills, K. A.; Neininger, N.; Pedlar, A.
Bibcode: 2002A&A...383...56G
Altcode:
  The fueling of the starburst in M 82 may be related to a stellar
  bar which pushes gas towards the center where it forms stars. The
  observation by McKeith et al. (1993) of the near-IR Ca II photospheric
  absorption line allows a direct velocity measurement of the stars in M
  82, and provides by this a confirmation of the predicted x<SUB>1</SUB>
  and x<SUB>2</SUB>-orbits of the bar in M 82. From this and other
  observations we find that the mass of the x<SUB>2</SUB>-orbit stars
  is ~ 15% of the mass of the bar, and that the mass of the bar of 2x
  10<SUP>9</SUP> M<SUB>sun</SUB> is 20-40% of M 82's mass. This mass
  concentration of ~ 1 kpc extent at the center of M 82 underlines the
  dynamic importance of the bar.

Title: A Second Epoch of 86 GHz CMVA Polarimetry Observations of
    the Quasars 3C273 and 3C279
Authors: Attridge, J. M.; Wardle, J. F. C.; Homan, D. C.; Krichbaum,
   T. P.; Greve, A.
Bibcode: 2001AAS...199.9808A
Altcode: 2001BAAS...33.1454A
  Observations of 3C 273 and 3C 279 taken in April 2000 with the
  Coordinated Millimeter VLBI Array (CMVA) resulted in the first 86
  GHz VLBI total intensity (Stokes I) and linear polarization images
  of any source (Attridge 2001). As Faraday effects are proportional
  to λ <SUP>2</SUP>, 86 GHz data should be less affected by Faraday
  rotation and depolarization than lower frequency data. The four
  antenna (FD, LA, PT, KP-12m) data defy the expectation that increased
  levels of linear polarization will be found in the cores of quasars
  at high frequencies, for both 3C 273 and 3C 279 display low levels
  of polarization in their cores at 86 GHz. In fact, 3C 273 displays
  no measurable linear polarization within a limit of 1%. The lack of
  significant linear polarization in the cores of 3C 273 and 3C 279, as
  well as the high rotation measures (&gt;1000 rad m<SUP>-2</SUP>) derived
  for the cores of many quasars (including 3C 273 and 3C 279) by Taylor
  (1998, 2000) suggest the presence of parsec-sized Faraday screens with
  organized magnetic fields near the quasar cores. If 3C 273's core is
  depolarized by Faraday effects alone, the dispersion of the rotation
  measure is ≳ 90000 rad m<SUP>-2</SUP> in the core. Alternately,
  depolarization can be explained in the case where 89% of the magnetic
  energy is contained in a tangled magnetic field. A second epoch of
  86 GHz CMVA polarization observations is presented. Data were taken
  in April 2001, almost exactly one year after the previous epoch, and
  with twice as many antennas. In addition to confirming the previous
  results, the superior resolution provided by the additional antennas
  allows further restriction of the sizes of the Faraday screens in the
  cores of 3C 273 and 3C 279. CMVA research at Haystack Observatory is
  sponsored by the National Science Foundation.

Title: Thermal model calculations of enclosures for millimeter
    wavelength radio telescopes
Authors: Greve, A.; MacLeod, G.
Bibcode: 2001RaSc...36.1111G
Altcode:
  Millimeter wavelength radio telescopes require a high surface
  and pointing precision, which in steerable open-air telescopes is
  obtained by a stiff or homologous construction and elaborate thermal
  control. The perturbing thermal loads and wind loads can also be reduced
  by protecting the telescope by a radome or astrodome, as applied
  on several operating telescopes. However, for the new generation
  telescopes of 30-m to 50-m diameter the radome or astrodome is very
  large and costly, and it is a priori not certain to which extent the
  internal thermal climate must be controlled, for instance, by forced
  air-conditioned ventilation, to obtain a telescope of good radio
  performance. We present data from the Onsala and Haystack radomes
  to illustrate agreement between measurements and thermal model
  calculations, and we use similar calculations to investigate the
  thermal behavior of a very large astrodome and radome. The accuracy
  of the calculations is sufficient for design and operational purposes.

Title: HI Absorption in NGC 2146 Observed with MERLIN
Authors: Tarchi, A.; Neininger, N.; Klein, U.; Pedlar, A.; Greve, A.
Bibcode: 2001ASPC..230..507T
Altcode: 2001gddg.conf..507T
  No abstract at ADS

Title: Radio interferometric observations of NGC 2146
Authors: Tarchi, A.; Neininger, N.; Greve, A.; Klein, U.; Garrington,
   S. T.; Muxlow, T. W. B.; Pedlar, A.; Glendenning, B. E
Bibcode: 2001IAUS..205..180T
Altcode:
  We present a high-resolution 5-GHz radio continuum map of the starburst
  galaxy NGC 2146 made with MERLIN and the VLA (A-array). Our observations
  detect 18 compact sources, and resolves 7 of them. Additional 1.6-GHz
  MERLIN observations disclose 9 sources coincident in position with
  those detected at 5 GHz, which allows us to derive their spectral
  indices. Only 3 sources have indices consistent with synchrotron
  emission from supernova remnants or radio supernovae, while the
  others have very steep inverted spectra. We suggest that the sources
  with positive spectral index are optically thick ultra-compact and/or
  ultra-dense H II regions with high electron densities and high emission
  measures (EM &gt; 10<SUP>7</SUP> cm<SUP>-6</SUP> pc). When compared with
  M 82, the galaxy NGC 2146 lacks however a large number of supernova
  remnants. We suggest that NGC 2146 is experiencing a burst of star
  formation stronger than that in M 82, but being in a younger phase. In
  this phase, only few stars have already exploded, whereas the others
  cause strong thermal emission from compact, optically thick ionized
  gas regions, around the young super starclusters. An alternative
  scenario with strong free-free absorption at 1.6 GHz from foreground
  ionized gas with very high emission measures (EM &gt; 10<SUP>8</SUP>
  cm<SUP>-6</SUP> pc) is discussed.

Title: Compact Radio Sources in NGC 2146
Authors: Tarchi, A.; Neininger, N.; Klein, U.; Greve, A.; Garrington,
   S. T.; Muxlow, T. W. B.; Pedlar, A.; Glendenning, B. E.
Bibcode: 2001ASPC..230..509T
Altcode: 2001gddg.conf..509T
  No abstract at ADS

Title: A high-frequency and multi-epoch VLBI study of 3C 273
Authors: Krichbaum, T. P.; Graham, D. A.; Witzel, A.; Zensus, J. A.;
   Greve, A.; Grewing, M.; Marscher, A.; Beasley, A. J.
Bibcode: 2001ASPC..250..184K
Altcode: 2001astro.ph..3443K; 2001pfrg.conf..184K
  We show results from a 7 year VLBI monitoring programme of 3C273 at
  millimeter wavelengths. We find evidence for component acceleration,
  motion or rotation of fluid dynamical patterns in the VLBI jet, and
  evidence for an outburst-ejection relation between Gamma-ray flares
  and the appearance of new jet components.

Title: Properties of the ISM in and around NGC2146 (Oral Contribution)
Authors: Neininger, N.; Tarchi, A.; Greve, A.
Bibcode: 2001dge..conf..157N
Altcode:
  No abstract at ADS

Title: The minor axis outflow of NGC 2146
Authors: Greve, A.; Neininger, N.; Tarchi, A.; Sievers, A.
Bibcode: 2000A&A...364..409G
Altcode: 2000astro.ph.10116G
  X-ray and optical observations have shown that the supernova explosions
  and stellar winds of the starburst in NGC 2146 produce an outflow of hot
  material along the minor axis. This outflow is expected to have a more
  or less conical shape, on either side of the galactic plane, and cone
  walls of cooler material where the outflow is in shock contact with
  halo gas. We attempt to determine the geometry (diameter at the base
  and opening angle) and the physical parameters (velocity and density)
  of the material in the cone walls from the optical emission line and
  radio observations presented here, and from published X-ray, radio,
  and optical observations. We compare the outflow of NGC 2146 with the
  outflow of M 82.

Title: 86 GHz VLBI survey of compact radio sources
Authors: Lobanov, A. P.; Krichbaum, T. P.; Graham, D. A.; Witzel,
   A.; Kraus, A.; Zensus, J. A.; Britzen, S.; Greve, A.; Grewing, M.
Bibcode: 2000A&A...364..391L
Altcode:
  We present results from 86 GHz VLBI observations of 28 compact radio
  sources made in April 1993. All but two of the observed objects are
  active galactic nuclei. The remaining two objects are the galactic
  center Sgr A<SUP>*</SUP> and the X-ray binary star Cygnus X-3. Of
  the observed sources, 26 have yielded fringe detections. We present
  correlated flux densities, estimate the maximum observed brightness
  temperatures, and provide single Gaussian component model fits. Out
  of the 17 sources with good uv-coverages, 3 are without detectable
  structural details (0642+449, 0716+714, and Cygnus A), 3 have little
  closure phase information (4C67.05, 1823+568, and 1928+738), and the
  remaining 11 have been imaged. We study the brightness temperatures,
  T_b, of the observed sources, and apply a basic population model with a
  single value of the intrinsic brightness temperature, T_0, in order to
  reproduce the observed distribution of T_b. Our data are consistent with
  a population of sources that have T<SUB>0</SUB>&lt;= 5x 10<SUP>10</SUP>
  K in the jets, and T<SUB>0</SUB> ~ 1-4x 10<SUP>11</SUP> K in the VLBI
  cores. The observed T_b are also correlated with the apparent speeds
  measured in the jets. For comparison, we apply the same population
  scenario to a larger sample of 132 AGN observed with VLBI at 15 GHz,
  and show that the distribution of brightness temperatures from that
  sample is consistent with the intrinsic brightness temperature of
  T<SUB>0</SUB> = 5.3x 10<SUP>11</SUP> K. The observed decrease of T_b
  along the jets can be reproduced by adiabatic losses in relativistic
  shocks embedded in the

Title: VizieR Online Data Catalog: 86GHz VLBI survey of compact
    radio sources (Lobanov+ 2000)
Authors: Lobanov, A. P.; Krichbaum, T. P.; Graham, D. A.; Witzel,
   A.; Kraus, A.; Zensus, J. A.; Britzen, S.; Greve, A.; Grewing, M.
Bibcode: 2000yCat..33640391L
Altcode:
  File table1 contains the list of observed sources, providing the
  source coordinates (J2000) and redshift, detection status, type,
  optical magnitude, and brightness temperature of the radio emission. <P
  />File table4 contains the description of the VLBI data, and provide the
  observed total and correlated flux densities, the parameters of single
  gaussian component model fits, and the parameters of hybrid images
  of the observed sources. <P />File table5 contains multicomponent
  model fits for the sources with detected extended structures and
  the brightness temperatures derived from these model fits. <P />(3
  data files).

Title: Radio supernovae, supernova remnants and H II regions in NGC
    2146 observed with MERLIN and the VLA
Authors: Tarchi, A.; Neininger, N.; Greve, A.; Klein, U.; Garrington,
   S. T.; Muxlow, T. W. B.; Pedlar, A.; Glendenning, B. E.
Bibcode: 2000A&A...358...95T
Altcode: 2000astro.ph..4083T
  We present a high-resolution 5-GHz radio continuum map of the starburst
  galaxy NGC 2146 made with MERLIN and the VLA (A-array), in a search
  of radio supernovae and supernova remnants expected to be already
  produced by the most massive stars in the starburst. At 5 GHz, about
  20 point sources were detected earlier by Glendenning &amp; Kronberg
  (1986) in the central 800 pc of NGC 2146. Our observations with higher
  sensitivity and resolution made with MERLIN and the VLA confirm the
  detection of 18 sources, and resolve 7 of them. Additional 1.6-GHz
  MERLIN observations disclose 9 sources coincident in position
  with those detected at 5 GHz, which allows us to derive their
  spectral indices α <SUB>1.6</SUB><SUP>5</SUP>, (S<SUB>ν </SUB> ~
  ν <SUP>alpha </SUP>). Only 3 sources have indices (alpha &lt; 0)
  consistent with synchrotron emission from supernova remnants or radio
  supernovae, while the others have very steep inverted spectra (alpha
  &gt; 0). We suggest that the sources with positive spectral index are
  optically thick ultra-compact and/or ultra-dense H II regions with high
  electron densities and high emission measures (EM &gt; 10<SUP>7</SUP>
  cm<SUP>-6</SUP> pc). Minimum energy requirements indicate that these
  regions may contain up to 1000 equivalent stars of type O6, comparable
  to the number of stars found in super starclusters. When compared with
  M 82, the galaxy NGC 2146 lacks however a large number of supernova
  remnants. We suggest that NGC 2146 is experiencing a burst of star
  formation stronger than that in M 82, but being in a younger phase. In
  this phase, only few stars have already exploded, whereas the others
  cause strong thermal emission from compact, optically thick ionized
  gas regions, around the young super starclusters. We may, however, not
  exclude an alternative scenario in which strong free-free absorption
  at 1.6 GHz in foreground ionized gas with very high emission measures
  (EM &gt; 10<SUP>8</SUP> cm<SUP>-6</SUP> pc) hides a certain number
  of supernova remnants, thus rendering for some sources the observed
  inverted spectra.

Title: Giant Molecular Clouds in the Dwarf Galaxy NGC 1569
Authors: Taylor, Chris L.; Hüttemeister, Susanne; Klein, Ulrich;
   Greve, Albert
Bibcode: 2000ASPC..215...51T
Altcode: 2000cegf.conf...51T
  No abstract at ADS

Title: Polarization Calibration and Imaging with the CMVA
Authors: Attridge, J. M.; Greve, A.; Krichbaum, T. P.
Bibcode: 1999AAS...195.1704A
Altcode: 1999BAAS...31.1398A
  VLBI polarization observations provide information about the structure,
  orientation, and evolution of the magnetic field in synchrotron emitting
  sources such as AGN. VLBI observations at centimeter wavelengths
  have shown that polarized relativistic shocks in radio jets appear
  as superluminal knots. In addition, magnetic field structures in
  the jets of BL Lacertae objects and quasars are quite different
  (e.g. Wardle et al. 1994, Ap.J., 437, 122; Cawthorne et al. 1993,
  Ap.J., 416, 519). Millimeter VLBI observations have the advantage of
  being relatively unaffected by Faraday rotation and opacity (Wardle et
  al. 1996, in the proceedings from the Millimeter-VLBI Science Workshop
  held at MIT). The high angular resolution provided by millimeter VLBI
  observations will allow new outbursts which feed the radio jets to be
  observed near to their point of origin. CMVA data of the quasars 3C273
  and 3C279 taken in April 1997 by Krichbaum, et al. are being used to
  develop and test a data calibration path for dual-polarization data
  which mimics the one presented for centimeter wavelengths in NRAO's AIPS
  software package. Here we present the current status of the calibration
  efforts, as well as preliminary results on 3C273 and/or 3C279. CMVA
  research at Haystack is sponsored by the National Science Foundation.

Title: Giant molecular clouds in the dwarf galaxy NGC 1569
Authors: Taylor, C. L.; Hüttemeister, S.; Klein, U.; Greve, A.
Bibcode: 1999A&A...349..424T
Altcode: 1999astro.ph..6427T
  We present CO 1-&gt;0 and 2-&gt;1 observations of the dwarf starburst
  galaxy NGC 1569 with the IRAM interferometer on Plateau de Bure. We
  find the CO emission is not spatially associated with the two super
  star clusters in the galaxy, but rather is found in the vicinity of
  an HII region. With the resolution of our data, we can resolve the CO
  emission into five distinct giant molecular clouds, four are detected
  at both transitions. In the 1-&gt;0 transition the sizes and linewidths
  are similar to those of GMCs in the Milky Way Galaxy and other nearby
  systems, with diameters ranging from ~ 40 to 50 pc and linewidths
  from 4 to 9 km s(-1) . The (2-1)/(1-0) line ratios range from 0.64 +/-
  0.30 to 1.31 +/- 0.60 in the different clouds. The lower line ratios
  are similar to those seen in typical Galactic GMCs, while values higher
  than unity are often seen in interacting or starburst galaxies. We use
  the virial theorem to derive the CO-H_2 conversion factor for three
  of the clouds, and we adopt an average value of 6.6 +/- 1.5 times the
  Galactic conversion factor for NGC 1569 in general. We discuss the
  role of the molecular gas in NGC 1569, and its relationship to the
  hot component of the ISM. Finally, we compare our observations with
  blue compact dwarf galaxies which have been mapped in CO.

Title: Stars, H II regions, and shocked gas in the bar of NGC 1530
Authors: Greve, A.; Reynaud, D.; Downes, D.
Bibcode: 1999A&A...348..394G
Altcode:
  We analyse long slit spectra taken along and perpendicular to the bar
  of the galaxy NGC 1530. Our data show that the H ii regions, around
  young massive stars that form in the shock-compressed gas, share the
  same kinematics as the molecular gas in the x_2 orbits at the center of
  the galaxy. Along the bar, the H ii regions are in the post-shock zone,
  downstream of the dust lanes that contain molecular gas. Outside of the
  H ii regions in the bar is faint, diffuse, ionized gas with a low Hα /
  [NII] and Hα / [SII] line ratio, which confirms the presence of shocks
  in the bar and supports a shock origin of the dust lanes. The measured
  spatial variation of the Hα and [NII] line intensity is consistent
  with the distribution of molecular gas along the dust lanes and its
  high concentration near the first inner Lindblad resonance. From an
  I-B image, we derive the surface brightness along the bar which we
  interpret as the stellar distribution. We use these data to estimate
  the mass in the various structural components of the bar. The mass of
  the stars and gas in the bar is 4x 10(10) M_sun, or 12% of the total
  mass of the galaxy.

Title: Proposed identification of Hubble Deep Field submillimeter
    source HDF 850.1
Authors: Downes, D.; Neri, R.; Greve, A.; Guilloteau, S.; Casoli,
   F.; Hughes, D.; Lutz, D.; Menten, K. M.; Wilner, D. J.; Andreani,
   P.; Bertoldi, F.; Carilli, C. L.; Dunlop, J.; Genzel, R.; Gueth,
   F.; Ivison, R. J.; Mann, R. G.; Mellier, Y.; Oliver, S.; Peacock,
   J.; Rigopoulou, D.; Rowan-Robinson, M.; Schilke, P.; Serjeant, S.;
   Tacconi, L. J.; Wright, M.
Bibcode: 1999A&A...347..809D
Altcode: 1999astro.ph..7139D
  The IRAM Interferometer has been used to detect the submillimeter
  source HDF 850.1 found by Hughes et al. (1998) in the Hubble Deep
  Field. The flux density measured at 1.3 mm (236 GHz) is 2.2+/- 0.3
  (1sigma ) mJy, in agreement with the flux density measured at the
  JCMT. The flux densities and upper limits measured at 3.4, 2.8,
  1.3, 0.85, and 0.45 mm show that the emission comes from dust. We
  suggest that the 1.3 mm dust source is associated with the optical
  arc-like feature, 3-593.0, that has a photometric redshift z~ 1.7. If
  the HDF 850.1 is at this redshift and unlensed, its spectral energy
  distribution, combined with that of 3-593.0, matches closely that of
  the ultraluminous galaxy VII Zw 31. Another possibility is that the
  dust source may be gravitationally lensed by the elliptical galaxy
  3-586.0 at z~ 1. The position of the dust source agrees within the
  errors with that of the tentative VLA radio source 3651+1226.

Title: Millimeter-VLBI science workshop
Authors: Greve, A.; Krichbaum, T. P.
Bibcode: 1999mvlb.conf.....G
Altcode:
  No abstract at ADS

Title: 2nd millimeter-VLBI science workshop
Authors: Greve, A.; Krichbaum, T. P.
Bibcode: 1999smvs.work.....G
Altcode:
  No abstract at ADS

Title: Status of Polarization Observations with CMVA
Authors: Attridge, J. M.; Greve, A.; Krichbaum, T. P.
Bibcode: 1999smvs.work...13A
Altcode:
  No abstract at ADS

Title: The beam pattern of the IRAM 30-m telescope. (a reflector
    with several surface error distributions)
Authors: Greve, A.; Kramer, C.; Wild, W.
Bibcode: 1998A&AS..133..271G
Altcode:
  Total power scans across the Moon around New Moon (mostly day time)
  and Full Moon (night time) at 3.4 mm (88 GHz), 2.0 mm (150 GHz), 1.3
  mm (230 GHz), and 0.86 mm (350 GHz) wavelength are used to derive the
  beam pattern of the IRAM 30-m telescope to a level of approximately
  -30 dB (0.1%) and, dependent on wavelength, to a full width of 1000 -
  1400''. From the reflector surface construction and application of the
  antenna tolerance theory we find that the measurable beam consists
  of the diffracted beam, two underlying error beams which can be
  explained from the panel dimensions, and a beam deformation mostly due
  to large-scale transient residual thermal deformations of the telescope
  structure. In view of the multiple beam structure of the 30-m telescope,
  and of other telescopes with a similar reflector construction of
  (mini-)panels and panel frames, we summarize the antenna tolerance
  theory for the influence of several independent surface/wavefront
  deformations. This theory makes use of different correlation lengths,
  which in essence determine the independent error distributions, and
  of the wavelength-scaling of the diffracted beam and of the error
  beams. From the Moon scans we derive the parameters for calculation
  of the 30-m telescope beam in the wavelength range 3 mm to 0.8 mm as
  required for the reduction of astronomical observations, in particular
  of extended sources. The parameters of the beam are primarily for the
  time after July 1997 when the reflector was re-adjusted and improved
  to the illumination weighted surface precision of sigma _T = 0.065 -
  0.075 mm. In the Appendix we explain the choice for this analysis of
  scans taken around New Moon and Full Moon.

Title: The gain-elevation correction of the IRAM 30-m telescope
Authors: Greve, A.; Neri, R.; Sievers, A.
Bibcode: 1998A&AS..132..413G
Altcode:
  The residual surface deformations of an optimized homologous radio
  reflector produce an elevation dependent gain variation for which
  astronomical observations must be corrected. For the IRAM 30-m telescope
  we provide information, and an example, how to correct observations
  of point-like and extended sources. We find agreement between the
  gain-elevation dependence predicted from the finite element structural
  calculations and radiometric measurements on the telescope.

Title: VLBI observations of the galactic center source SGR A* at 86
    GHz and 215 GHz
Authors: Krichbaum, T. P.; Graham, D. A.; Witzel, A.; Greve, A.; Wink,
   J. E.; Grewing, M.; Colomer, F.; de Vicente, P.; Gomez-Gonzalez, J.;
   Baudry, A.; Zensus, J. A.
Bibcode: 1998A&A...335L.106K
Altcode:
  We have observed and detected Sgr A* with VLBI at 86 GHz and at 215 GHz
  in March 1995. At 86 GHz the measured closure phase is close to zero,
  consistent with a point-like or symmetric structure of 190 +/- 30 mu
  as in size. At 215 GHz we have detected Sgr A* with a signal-to-noise
  ratio of 6. This yields a tentative size estimate of 110 +/- 60 mu as
  which, despite of a limited calibration accuracy and uncertainty in
  the origin of the mm/sub-mm total flux density excess, lies well above
  the scattering size of 20 mu as at this frequency. The intrinsic size
  of Sgr A* thus appears to be 17 +/- 9 Schwarzschild radii for a 2.6 *
  10^6 M_solar black hole.

Title: Results of the SEST key programme: CO in the Magellanic
    Clouds. VII. 30 Doradus and its southern H II regions
Authors: Johansson, L. E. B.; Greve, A.; Booth, R. S.; Boulanger,
   F.; Garay, G.; de Graauw, Th.; Israel, F. P.; Kutner, M. L.; Lequeux,
   J.; Murphy, D. C.; Nyman, L. -A.; Rubio, M.
Bibcode: 1998A&A...331..857J
Altcode:
  We have mapped the (12) CO(1-0) emission from the 30 Doradus region in
  the Large Magellanic Cloud with the Swedish-ESO Submillimetre Telescope
  (SEST). The regions investigated include the central part of the 30
  Dor nebula, and the southern Hii regions N 158C, N 159, and N 160. In
  addition, a few prominent CO clouds have been studied in the (2-1)
  and (3-2) transitions of CO. The southern area shows the strongest
  (12) CO(1-0) emission, a factor of 3 higher than towards the central
  part of 30 Dor. A non-LTE analysis of the CO emission from a sample
  of clouds indicate kinetic temperatures between 10 and 50 K; the
  highest temperatures are found close to the 30 Dor nebula. We have
  estimated the CO-H<SUB>2</SUB> conversion factor for the two areas,
  separately, under the assumption that the virial mass, determined
  from CO parameters, reflects the total molecular mass. We find an
  unexpectedly small difference between the two areas. This is explained
  as a bias effect. Based on results collected at the European Southern
  Observatory, La Silla, Chile

Title: VLBI observations of CygnusA with sub-milliarcsecond resolution
Authors: Krichbaum, T. P.; Alef, W.; Witzel, A.; Zensus, J. A.; Booth,
   R. S.; Greve, A.; Rogers, A. E. E.
Bibcode: 1998A&A...329..873K
Altcode:
  We present new images of the two-sided VLBI-structure of the radio
  galaxy CygnusA at 1.6GHz, 22GHz and 43GHz. The maps show the jet and
  counter-jet of CygnusA on scales from ~ 400 to 0.1 milliarcseconds,
  corresponding to projected sizes of ~ 300pc to 0.07pc. Our best 22GHz
  image shows a small (few degree) misalignment of the VLBI-jets with
  the kpc-jets, longitudinal oscillations of the jet's ridge line with
  amplitudes of &lt;= 0.6mas, and transverse oscillations of the jet's
  width with amplitudes of 0.2 - 0.3mas. At distances of &lt; 15mas from
  the core, both jets expand at an opening angle of ~ 5^{\circ}. Between
  22 and 43GHz the core has an inverted spectrum. The spectrum of the
  jet appears steep, that of the counter-jet relatively flat. &gt;From
  two 22GHz observations we find evidence for apparent acceleration (from
  0.1c to 0.7c) along the jet. The acceleration could be jet-intrinsic or
  related to phase velocities. In the counter-jet structural variations
  seem also to be present, but cannot accurately be determined. Between
  1.6GHz and 43GHz the jet-to-counter-jet ratio R is frequency dependent
  with a maximum of R =~ 5 near 5GHz and a smaller ratio of R =1 - 2 at
  1.6GHz and 43GHz. This can be interpreted as an effect of absorption
  by a partially opaque inclined absorber (e.g. a disk or a torus)
  obscuring the counter-jet but not the jet. With an absorption corrected
  intrinsically small jet-to-counter-jet ratio, CygnusA could be oriented
  at a relatively large angle to the line of sight (theta &gt; 80^{\circ},
  for R &lt;2) with jet velocities in the range 0.2 h &lt;= beta &lt;
  1 (H_0= 100 * h(-1) km sec(-1) Mpc(-1) ).

Title: The high-frequency compact radio structure of the peculiar
    quasar 4C 39.25.
Authors: Alberdi, A.; Krichbaum, T. P.; Graham, D. A.; Greve,
   A.; Grewing, M.; Marcaide, J. M.; Witzel, A.; Booth, R. S.; Baath,
   L. B.; Colomer, F.; Doeleman, S.; Marscher, A. P.; Rogers, A. E. E.;
   Schalinski, C. J.; Standke, K.
Bibcode: 1997A&A...327..513A
Altcode:
  We present new high angular resolution images of the compact non-thermal
  radio source 4C 39.25 obtained from VLBI observations at λ1.3cm,
  λ7mm, and λ3mm wavelengths. These maps and Gaussian model-fits show
  that the milli-arcsecond to sub-milliarcsecond structure of 4C 39.25
  consists of a complex bent core-jet structure with embedded moving
  and stationary VLBI components. Facilitated by the small observing
  beams and high angular resolutions obtained at mm-wavelengths, we
  measured the relative positions of the jet components with an accuracy
  of a few hundred micro-arcseconds. This allows the detailed followup
  of the ongoing merging process of a westward superluminally moving
  component (b_) with a stationary component a_, located at ~2.9 mas
  east of the putative core d_. In contrast to the other components
  of the structure with steeper spectra, the westernmost component d_
  exhibits an inverted spectrum peaking between λ7mm and λ3mm, thus
  further supporting its identification as the VLBI core, self-absorbed at
  longer wavelengths. From two VLBI maps obtained nearly simultaneously at
  λ7mm and λ1.3cm, we made the first spectral index map of 4C 39.25 in
  this wavelength regime. The main characteristics of the spectral index
  distribution of the jet are pronounced changes of the spectral index
  between orientations parallel and transverse to the jet axis. Near
  the merging components a_ and b_ the spectral index steepens with
  increasing separation from d_. However, in the bridge of emission c_,
  which connects d_ with a_ and b_, the spectral index gradient has a
  direction transverse to the jet axis, suggesting a frequency dependent
  jet curvature and edge-brightening. A brief discussion of this behaviour
  within current jet models is presented.

Title: The Paschen decrement as a density indicator in MWC 349.
Authors: Thum, C.; Greve, A.
Bibcode: 1997A&A...324..699T
Altcode:
  We present new observations of the Paschen series hydrogen recombination
  lines in the circumstellar shell of MWC 349. We find the Paschen
  decrement to be characteristic of a very high density plasma,
  n_e_~10^8^cm^-3^, indicating the origin of the higher quantum number
  Paschen lines in the dense corona of the circumstellar disk. The
  strength of the masing hydrogen recombination α-lines detected
  previously in the high density plasma of this source is strongly
  dependent on n_e_, since the n_e_ for maximum amplification increases
  systematically for decreasing quantum numbers n. The absence of gas with
  n_e_ significantly higher than 10^8^cm^-3^ implies that the strength of
  recombination α-line masers may peak near n=20 (λ=400μm) and that the
  shorter wavelength transitions may mase only at reduced efficiency. The
  good agreement over a large range of n between the observed and the
  theoretical Paschen decrement shows that any departure from standard
  recombination theory, possibly due to the strong IR radiation field
  of the circumstellar disk, must be small.

Title: Cassegrainian Gregorian-type null correctors for surface
    measurements of radio telescope reflectors
Authors: Greve, A.
Bibcode: 1997ApOpt..36.5283G
Altcode:
  The (sub)millimeter wavelength radio observatory of the next generation
  will probably be an interferometer array of some 50 telescopes with
  parabolic reflectors 10-15 m in diameter. At this scale of mass
  production it is convenient to have at hand for workshop assembly a
  reflector surface measurement technique that is precise and easy to
  operate. We discuss the possibility of reflector measurements based on
  10.6-μm CO2 laser interferometry using Cassegrainian/Gregorian-type
  null correctors.

Title: 215 GHz VLBI observations of bright Active Galactic Nuclei.
Authors: Krichbaum, T. P.; Graham, D. A.; Greve, A.; Wink, J. E.;
   Alcolea, J.; Colomer, F.; de Vicente, P.; Baudry, A.; Gomez-Gonzalez,
   J.; Grewing, M.; Witzel, A.
Bibcode: 1997A&A...323L..17K
Altcode:
  We report the detection of 6 active galactic nuclei, and also
  the marginal detection of the galactic center radio source SgrA*,
  in 215GHz VLBI observations between the IRAM 30m telescope on Pico
  Veleta and one 15m antenna of the IRAM Plateau de Bure interferometer
  (~0.3mas fringe spacing). In this (second) 1.4mm VLBI-experiment we
  find source dependent ratios between the total and correlated flux
  densities in the range of 10-35%, indicating partly resolved brightness
  distributions on sub-milliarcsecond scales. In view of the calibration
  uncertainties and the limited uv-coverage at this high frequency this
  needs further confirmation. The present detection limit of ~0.4-0.5Jy
  opens the possibility for more extended 1.4mm VLBI experiments, in
  particular with phased millimeter arrays.

Title: Millimetre continuum measurements of extragalactic radio
    sources. IV. Data from 1993-1994
Authors: Reuter, H. -P.; Kramer, C.; Sievers, A.; Paubert, G.; Moreno,
   R.; Greve, A.; Leon, S.; Panis, J. F.; Ruiz-Moreno, M.; Ungerechts,
   H.; Wild, W.
Bibcode: 1997A&AS..122..271R
Altcode:
  Radio flux densities are presented for 118 extragalactic radio sources
  monitored at 90, 142 and 230 GHz with the IRAM 30 m telescope during
  1993-1994. For the most frequently observed sources we show light curves
  including 30 m-measurements published in previous papers. Tables 1 and
  4 are available electronically at the CDS via anonymous ftp 130.79.128.5
  or at http://cdsweb.u-strasbg.fr/Abstract.html.

Title: Millimeter VLBI at IRAM
Authors: Greve, A.
Bibcode: 1997mvlb.work..107G
Altcode:
  No abstract at ADS

Title: Coma correction of a wobbling subreflector.
Authors: Greve, A.; Lefloch, B.; Penalver, J.
Bibcode: 1996ITAP...44.1642G
Altcode:
  Radio astronomical observations at millimeter wavelengths with
  Cassegrain telescopes often use on-source/off-source measurements with
  a wobbling subreflector to eliminate the influence of the Earth's
  atmosphere. The tilt of the subreflector produces the required beam
  throw, but also a coma-like wavefront deformation noticeable as a
  degradation of the beam pattern and a reduction of the main beam
  power. The authors demonstrate, with measurements made with the IRAM
  30-m telescope at 1.3 mm wavelength (230 GHz) of the quasi-point-like
  source Mars and the extended source Saturn, that it is possible to
  eliminate (to a large extent) this wavefront deformation when using
  a near-focus corrector, on the 30-m telescope conveniently located on
  the co-rotating Nasmyth mirror.

Title: On the consistency of solar limb darkening observations at
    UV wavelengths (2000-3300A).
Authors: Greve, A.; Neckel, H.
Bibcode: 1996A&AS..120...35G
Altcode:
  Limb darkening observations are important for the construction and
  verification of solar model atmospheres. We investigate the consistency
  of solar limb darkening data, published for the UV wavelength region
  between 2000 and 3300A, from the comparison of F/I_0_ ratios based
  either on direct limb darkening observations or on absolute irradiance
  (F) and disk-center intensity (I_0_) measurements. There exists
  a discrepancy between the limb darkening data of Moe &amp; Milone
  (1978ApJ...226..301M) and other, direct or indirect, limb darkening
  observations.

Title: VizieR Online Data Catalog: mm-monitoring of radio sources
    IV. (Reuter+ 1997)
Authors: Reuter, H. -P.; Kramer, C.; Sievers, A.; Paubert, G.; Moreno,
   R.; Greve, A.; Leon, S.; Panis, J. F.; Ruiz-Moreno, M.; Ungerechts,
   H.; Wild, W.
Bibcode: 1996yCat..41220271R
Altcode:
  Radio flux densities are presented for 118 extragalactic radio sources
  monitored at 90, 142 and 230GHz with the IRAM 30m telescope during
  1993-1994. For the most frequently observed sources we show light curves
  including 30 m-measurements published in previous papers, Steppe et
  al. (1988A&amp;AS...75..317S; 1992A&amp;AS...96..441S and and 1993,
  Cat. &lt;J/A+AS/102/611&gt;) (2 data files).

Title: NGC 1569: the molecular and ionized gas near the superluminous
    star clusters A and B.
Authors: Greve, A.; Becker, R.; Johansson, L. E. B.; McKeith, C. D.
Bibcode: 1996A&A...312..391G
Altcode:
  The starburst in the irregular galaxy NGC 1569 has produced two
  superluminous star clusters A and B which strongly influence their
  surroundings through UV radiation, stellar winds, supernova explosions,
  and an outflow of very hot gas. Close to A and B is located the most
  prominent HII region of NGC 1569; our CO observations indicate that it
  contains ~ 2x10^6^M<SUB>sun</SUB>_ molecular gas which probably still
  feeds star formation of its internal stellar cluster. When comparing
  the molecular gas mass, calculated for Galactic conditions, and the
  virial mass we obtain a conversion factor ~ 20 times higher than the
  Galactic value. However, we believe that the molecular clouds near the
  stellar clusters are not in kinematic equilibrium so that the virial
  theorem does not apply; we therefore reject this conversion factor as
  unrealistic. Our spectroscopic observations seem to indicate an optical
  counterpart of the Hi cavity around A, though being smaller in extent,
  and a surrounding shell of ionized gas of ~ 50 pc diameter. The compact
  galaxy NGC 1705 contains a stellar cluster even brighter than A and
  B. We did not detect CO in this galaxy.

Title: The pointing of the IRAM 30-m telescope.
Authors: Greve, A.; Panis, J. -F.; Thum, C.
Bibcode: 1996A&AS..115..379G
Altcode:
  The original pointing model of the IRAM 30-m millimeter wavelength radio
  telescope is based on nine parameters which are updated from special
  pointing measurements made approximately every two weeks. The pointing
  models derived from these measurements provide a pointing accuracy
  of 3.5" (rms) which, however, degrades slowly with time. Application
  by the observer of instantaneous pointing corrections recovers the
  inherently precise operation of the telescope. The data analyzed here
  show that the number of pointing parameters used for the 30-m telescope
  can be reduced to six because the astronomical positions of pointing
  sources are today accurately known, and because the telescope does not
  show hysteresis or long-term irreversible changes of its mechanical
  behaviour so that the gravitational bending can be described by a
  unique and time-independent function, as should be the case. There are
  indications that the inclination of the azimuth axis is influenced by
  seasonal thermal effects, which merit further monitoring for eventual
  quasi real time correction. The other pointing parameters show random
  variations in time which makes it difficult to trace any particular
  source which sets their ultimate accuracy, although we suspect residual
  thermal effects to be the main source of perturbation.

Title: Near-focus active optics: An inexpensive method to improve
    millimeter-wavelength radio telescopes
Authors: Greve, A.; Baars, J. W. M.; Peñalver, J.; LeFloch, B.
Bibcode: 1996RaSc...31.1053G
Altcode:
  The application of active and adaptive optics allows the construction
  of large diameter lightweight optical telescopes for observations
  below the seeing limit of the atmosphere. Active wavefront correction
  in a Cassegrain/Gregory-type radio telescope can be made with
  a deformable main reflector or deformable subreflector. Here we
  suggest the possibility of correcting spatially large-scale wavefront
  deformations with a small size corrector located near the focus
  of the telescope. Using representative examples of the Institut
  de Radioastronomie Millimetrique (IRAM, Spain) 30-meter diameter,
  millimeter-wavelength telescope, we calculate the improvement expected
  from the correction of (1) the systematic component in homology
  deformations, (2) the large-scale residual errors of a reflector
  adjustment, and (3) the beam degradation experienced in observations
  with a wobbling subreflector. The improvement in surface/wavefront
  precision obtained from piston correction with a corrector of some 50
  elements is of the order of 30%-40%. We investigate in particular the
  systematic component of homology deformations, their representation
  by low-order Zernike polynomials, and their elimination by near-focus
  correction. We study in detail the homology deformations of the IRAM
  30-m reflector.

Title: Fe I lines in late type stellar UV spectra.
Authors: Greve, A.; McKeith, C. D.
Bibcode: 1995A&A...302..165G
Altcode:
  It has been suggested that Fe I lines may constitute a major part of
  the many absorption lines observed in the (near-UV) solar spectrum and
  in those of late type stars. We use the table of Fe I lines recently
  measured in the laboratory by Nave et al. (1994) and examine the
  solar spectrum between 2756-2831A observed by us previously with the
  highest spectral resolution to date, R=1.75x10^5^. We exploit this
  existing observation since only such high spectral resolution allows
  sufficient isolation of weak lines in an underlying haze of absorption
  features. In this solar spectrum we detect ~90% of the tabulated
  Fe I lines. Investigations of this kind are relevant, for instance,
  to primordial abundances of beryllium and boron in late type metal
  poor halo stars requiring complete model atmosphere line opacities
  and discrimination of possible line blending. We illustrate the case
  of Be with the spectrum of the late type star HD 165908 observed
  with R=~5x10^4^.

Title: 215 GHz VLBI observations: Detection of fringes on the 1147
    KM baseline Pico Veleta-Plateau de Bure
Authors: Greve, A.; Torres, M.; Wink, J. E.; Grewing, M.; Wild, W.;
   Alcolea, J.; Barcia, A.; Colomer, F.; de Vincente, P.; Gomez-Gonzalez,
   J.; Lopez-Fernandez, I.; Graham, D. A.; Krichbaum, T. P.; Schwartz,
   R.; Standke, K. J.; Witzel, A.; Baudry, A.
Bibcode: 1995A&A...299L..33G
Altcode:
  In a VLBI test experiment between the IRAM 3Om telescope at Pico
  Veleta, Spain, and one 15-m telescope of the IRAM interferometer on
  Plateau de Bure, France, we detected fringes at 215 GHz with signal
  to noise ratios between 6 8 and 10.2. On this 1147km long distance,
  of 0.28-0.43 milli arcseconds projected fringe spacing at 215 GHz,
  we have 8 independent detections of the sources 3C273, 3C279 and
  2145+067 The clock and fringe rates at 215 GHz are consistent with
  those derived from VLBI measurements at 86 GHz made at the beginning
  or end of the 215 GHz observations. The coherence time at 215 GHz were
  of the order of 10 seconds, most probably limited by the atmosphere.

Title: The outflow in the halo of M 82.
Authors: McKeith, C. D.; Greve, A.; Downes, D.; Prada, F.
Bibcode: 1995A&A...293..703M
Altcode:
  New observations of emission and absorption lines along M 82's minor
  axis yield detailed radial velocity-position curves tracing the blowout
  of the superwind from the starburst region. The new velocity data
  provide good evidence for the acceleration of the wind in the energy
  input region (z&lt;300pc), for the wind becoming supersonic about
  300pc above and below the galactic plane, and tending to a constant
  velocity in the free wind zone at z&gt;300pc. Inflexion points in the
  velocity curves suggest that the blowout region has an hourglass shape,
  that is, the profile is cylindrical for z&lt;300pc, and flares out
  to a conical shape for z&gt;300pc. While most of the line emission
  comes from ionized gas moving on the surfaces of the blowout cones,
  some of it may be scattered, appearing near the systemic velocity. The
  stellar Ca II IR absorption lines appear near the systemic velocity at
  all distances along the minor axis. These lines may come mainly from
  late-type stars in the disk, with the radiation scattered by dust in
  the halo. Although a contribution from scattered light is definitely
  present, any explanation for the emission lines wholly in terms of
  scattered radiation from dust in a giant bipolar reflection nebula is
  immediately ruled out by a) the large blue shifts (-300 to -450km/s)
  relative to the systemic velocity of the galaxy, b) the monotonic
  variations of the velocity as a function of height above the galactic
  plane, c) the non-shifted, non-split, scattered stellar CaII IR lines,
  and d) the variation of the extinction-independent [SII] line ratios,
  which indicate a rapid decrease of electron density with height above
  the galactic plane. The superwind model accounts for these facts both
  qualtitatively and quantitatively.

Title: Spectroscopic studies of the disk and halo of M82.
Authors: McKeith, C.; Greve, A.; Downes, D.; Prada, F.
Bibcode: 1995ASIC..469..325M
Altcode: 1995osd..conf..325M
  No abstract at ADS

Title: Astigmatism in reflector antennas: measurement and correction
Authors: Greve, A.; Lefloch, B.; Morris, D.; Hein, H.; Navarro, S.
Bibcode: 1994ITAP...42.1345G
Altcode:
  We investigate astigmatism in Cassegrain antennas from cross scans
  through in-and-out-of-focus diffraction images of extended radio
  sources. The use of extended sources is of interest for large (mm
  wavelength) telescopes where the bright planets subtend a substantial
  fraction of the beam. The experimental and theoretical results
  presented here refer to the IRAM 30-m telescope and measurements at
  7.3 mm-1.3 mm wavelength; however, extrapolation to other telescopes
  is evident. We report on an experiment to correct the astigmatism
  (phase) at a position close to the focal plane of the telescope, i.e.,
  the flat surface of the corotating Nasmyth mirror.

Title: The exciting star of the small bubble N 120A in the Large
    Magellanic Cloud
Authors: Laval, A.; Gry, C.; Rosado, M.; Marcelin, M.; Greve, A.
Bibcode: 1994A&A...288..572L
Altcode:
  UV characteristics of the star BI 141 show that it is the exciting
  star of the nebula N 120A of the LMC. We determine its UV spectral
  classification as O_9.5_I and we derive the terminal velocity and
  mass-loss rate of its stellar wind, in agreement with the usual
  values found for galactic supergiants of the same spectral type. The
  energetic balance between the power of the stellar wind and the
  measured energetic input into the surrounding gas shows that the wind
  is largely the dominant factor for driving the bubble. The best model
  for the sustained bubble is the model with conservation of energy,
  (nonradiative shocked stellar winds). The discrepancy between the
  visible spectral classification B_3_I and the UV classification opens
  the questions of either the multiplicity or the variability of BI 141,
  and of its stellar wind.

Title: NGC 1569: identification from CA II infrared line spectra of
    the objects A, B as superluminous star clusters
Authors: Prada, F.; Greve, A.; McKeith, C. D.
Bibcode: 1994A&A...288..396P
Altcode:
  We present blue and near-infrared spectroscopic data which provide
  evidence that the stellar-like objects (called A and B) in the nucleus
  of NGC 1569 are star clusters. The Ca II infrared triplet absorption
  lines and the slope of the spectral continuum reveal that the star
  cluster B is in the red supergiant phase of the cluster evolution
  at an age of 12 Myr, while the star cluster A is in the blue star
  phase at an age of 13-20 Myr. Evidence for a stellar condensation
  is also found within the large H II region close to A as indicated
  by the Ca II triplet present in its near-infrared spectrum. We give
  reddening-corrected emission line ratios for this H II region.

Title: VizieR Online Data Catalog: Outflow in M82 halo (McKeith+,
    1995)
Authors: McKeith, C. D.; Greve, A.; Downes, D.; Prada, F.
Bibcode: 1994yCat..32930703M
Altcode:
  Not Available (2 data files).

Title: Disk brightness temperature of the planets at 43 GHz (and 43
    GHz flux densities of some continuum sources).
Authors: Greve, A.; Steppe, H.; Graham, D.; Schalinski, C. J.
Bibcode: 1994A&A...286..654G
Altcode:
  We have used the MPIfR 43 GHz (7 mm) Schottky receiver, installed in
  1991 on the IRAM 30-m telescope for VLBI observations, for flux density
  measurements of several planets in comparison with several Galactic
  and extra-galactic continuum sources, using as calibration standards
  the sources W3OH and NGC 7027. The disk brightness temperatures of
  the planets are derived from these flux densities.

Title: Design parameters and measured performance of the IRAM 30-m
    millimeter radio telescope.
Authors: Baars, J. W. M.; Greve, A.; Hein, H.; Morris, D.; Penalver,
   J.; Thum, C.
Bibcode: 1994IEEEP..82..687B
Altcode:
  The "Millimeter Radio Telescope" (MRT) is operated by the Institute for
  Radio Astronomy in the Millimeter range (IRAM) and is located at 2850-m
  altitude in the Sierra Nevada, near Granada, Spain. The authors compare
  the design computations with the characteristics of the telescope,
  derived from several years of operation and optimization. The success
  of the design is demonstrated by the observational experience.

Title: An investigation of extinction diagnostics towards the
    Orion Nebula.
Authors: Greve, A.; Castles, J.; McKeith, C. D.
Bibcode: 1994A&A...284..919G
Altcode:
  We present for the Orion nebula long-slit spectroscopic observations
  of emission lines in the wavelength regions 10 000-11 000 A and
  3700-7330 A. These wavelength regions contain the corresponding
  multiplet lines of common upper atomic level of hydrogen P_6_-H_6_
  (= P<SUB>gamma</SUB>_ -H<SUB>delta</SUB>_) and P_7_-H_7_ (=
  P<SUB>delta</SUB>_-H<SUB>epsilon</SUB>_) and of [S II] at 10 300
  A and 4072 A. From these lines the extinction A_V_ towards the
  Orion nebula is derived with minimal reliance on recombination
  line model calculations. We find good internal agreement for
  the extinction derived from the corresponding hydrogen and [S II]
  lines, except for deviations of the order of 20-30% for data based on
  H<SUB>epsilon</SUB>_ and P<SUB>delta</SUB>_, where deblending of the
  H<SUB>epsilon</SUB>_ line may be uncertain by this amount and the flux
  of the P<SUB>delta</SUB>_ line contains a similar error. There exists
  good agreement with the extinction derived from the other Paschen and
  Balmer line combinations. We also discuss in particular the method of
  extinction determination proposed by Allen (1979). However, we find
  no advantage from this over the other methods based on Paschen-Balmer
  lines and corresponding [S II] lines, neither from a greater precision
  achieved nor from the observational requirements.

Title: Wavelength-dependent Kinematics in the Dusty Inclined Galaxy
    NGC 2146
Authors: Prada, F.; Beckman, J. E.; McKeith, C. D.; Castles, J.;
   Greve, A.
Bibcode: 1994ApJ...423L..35P
Altcode:
  We present measurements of the apparent rotation curves of the dusty
  inclined spiral NGC 2146 taken using conventional long-slit spectroscopy
  in the red and near-infrared. The curve measured in Hα emission shows,
  with respect to that observed in [S III] λ9069, a series of dips in
  velocity which coincide in positions with dips in the intensity of
  Hα, and with the dust lanes evident in broad band images. A more
  detailed quantitative comparison, including a previously published
  velocity curve in Brγ (Hutchings et al. 1990), using a schematic
  model, supports the hypothesis that dust is causing the Hα/[S III]
  discrepancies and highlights the need to measure rotation curves of
  inclined galaxies as far into the infrared as techniques permit. The
  λ9069 [S III] emission reveals a zone in expansion at 190 pc from the
  nucleus (previously detected in Brγ but at lower spectral resolution
  and with consequently limited velocity diagnostics) whose kinematics and
  energetics are well explained in terms of an expanding "superbubble"
  due to a starburst. Finally we suggest, from the invariance of the
  velocity curve with wavelength at nucleocentric radii greater than 1500
  pc that our observations imply very limited observable dust extinction
  in the outer parts of the disk of NGC 2146.

Title: VizieR Online Data Catalog: Millimeter continuum of
    extragal. sources III. (Steppe+ 1993)
Authors: Steppe, H.; Paubert, G.; Sievers, A.; Reuter, H. P.; Greve,
   A.; Liechti, S.; Le Floch, B.; Brunswig, W.; Menedez, C.; Sanchez, S.
Bibcode: 1994yCat..41020611S
Altcode:
  Not Available (2 data files).

Title: MM Observations of Active Galactic Nuclei with a High
    Sensitivity VLB-Array
Authors: Schalinski, C. J.; Witzel, A.; Krichbaum, T. P.; Graham,
   D. A.; Standke, K. J.; Rogers, A. E. E.; Doleman, S.; Zensus, J. A.;
   Greve, A.; Bååth, L. B.; Booth, R. S.
Bibcode: 1994cers.conf...45S
Altcode:
  No abstract at ADS

Title: Millimeter continuum measurements of extragalactic radio
    sources. III.
Authors: Steppe, H.; Paubert, G.; Sievers, A.; Reuter, H. P.; Greve,
   A.; Liechti, S.; Le Floch, B.; Brunswig, W.; Menedez, C.; Sanchez, S.
Bibcode: 1993A&AS..102..611S
Altcode:
  This paper presents a catalog of 118 extragalactic radio sources
  observed at 90, 150 and 230 GHz from November 1990 to the end of
  1992. The figures contain flux densities for 83 sources from both
  previous catalogs (Steppe et al. 1988, Steppe et al. 1992) and this
  paper.

Title: First 43 GHz VLBI-observations with the 30-m radio telescope
    at Pico Veleta.
Authors: Krichbaum, T. P.; Witzel, A.; Graham, D. A.; Standke, K. J.;
   Schwartz, R.; Lochner, O.; Schalinski, C. J.; Greve, A.; Steppe, H.;
   Brunswig, W.; Butin, G.; Hein, H.; Navarro, S.; Penalver, J.; Grewing,
   M.; Booth, R. S.; Colomer, F.; Ronnang, B. O.
Bibcode: 1993A&A...275..375K
Altcode:
  A three station VLBI experiment performed at 43 GHz (λ= 7 mm
  wavelength) demonstrated the superior performance of the 30-m
  millimeter radio telescope of IRAM at Pico Veleta especially for
  mm-VLBI observations. Although primarily intended as a technical
  test, these first 43 GHz VLBI observations with Pico Veleta yielded
  new scientific results. A first VLBI map of Cygnus A (=3C 405) at 43
  GHz shows a core-jet-like structure of ~4 mas length, with several
  compact components embedded. The map also shows some evidence for
  jet bending near the core of about {DELTA}P.A. = 5-15^deg^. The
  apparent subluminal motion in the "inner jet" of 3C 84 (= NGC 1275)
  is confirmed and seems to show (apparent) acceleration along the jet
  from 21 000 km s^-1^ close to the nucleus to 114000 km s^-1^ at ~4 mas
  separation from the VLBI-core. The absence of any detectable counter-jet
  requires either a direct orientation of the jet towards the observer
  or a pronounced asymmetry between jet and counter-jet. In 3C 345 the
  apparent superluminal motion along bent trajectories of two recently
  ejected jet components (C6 and C7) was further monitored. Inspection
  of their paths indicates trajectories largely different from each other
  and from those of their precursors. These results and the detection of
  other extragalactic objects and galactic SiO-maser sources show that
  the participation of the IRAM 30-m radio telescope in VLBI observations
  at millimeter wavelengths greatly enhances the detection threshold
  and imaging capabilities of mm-VLBI.

Title: Global photometric structure of the Orion nebula.
Authors: Greve, A.; van Genderen, A. M.; Augusteijn, Th.
Bibcode: 1993A&AS...99..577G
Altcode:
  We present Walraven V BLUW photometric observations of the Orion
  nebula. For an idealized radial-symmetric nebula the brightness
  distribution decreases exponentially with distance from the Trapezium
  stars. The integrated brightness and color is calculated.

Title: Rotation of stars and gas in M 82.
Authors: McKeith, C. D.; Castles, J.; Greve, A.; Downes, D.
Bibcode: 1993A&A...272...98M
Altcode:
  New observations of near IR emission and absorption lines along M 82's
  major axis yield radial velocity-position curves that differ markedly
  from those derived from lines at visible wavelengths. For the central
  disk we find identical rotation for the gas and the stars, contrary
  to earlier results. The rotation derived from emission and absorption
  lines at visible wavelengths refer to outer regions of the galaxy
  since at these wavelengths the central disk is obscured by dust.

Title: The 86 GHz VLBI test with Pico Velat: first detection of
    quasar 3C454. 3 at 3 mm wavelength
Authors: Schalinski, C.; Greve, A.; Grewing, M.; Steppe, H.; Graham,
   D.; Krichbaum, T.; Witzel, A.; Alberdi, A.; Baath, L.; Booth, R. S.;
   Colomer, F.
Bibcode: 1993sara.conf..184S
Altcode:
  No abstract at ADS

Title: Thermal behavior of millimeter wavelength radio telescopes
Authors: Greve, Albert; Dan, Michel; Penalver, Juan
Bibcode: 1992ITAP...40.1375G
Altcode:
  Thermal protection applied to the IRAM 15-m mm-wavelength and 30-m
  mm-wavelength telescopes and their thermal behavior are discussed. The
  design of the passive/active thermal protection of these telescopes is
  based on dynamic time-dependent model calculations, which are explained
  and compared with in situ recorded temperatures of the telescope
  components. It is demonstrated that dynamic model calculations are
  capable of reproducing the observed thermal behavior of significant
  structural components with sufficient precision. It is pointed out
  that continued monitoring of the thermal behavior may lead to further
  improvements the performance of a telescope.

Title: Submillimeter Spectrum and Dust Mass of the Primeval Galaxy
    IRAS 10214+4724
Authors: Downes, D.; Radford, J. E.; Greve, A.; Thum, C.; Solomon,
   P. M.; Wink, J. E.
Bibcode: 1992ApJ...398L..25D
Altcode:
  We measured with the IRAM 30 m telescope the continuum flux of the
  extremely luminous primeval galaxy IRAS 10214+4724 at a wavelength of
  1.2 mm. This is the longest wavelength at which this galaxy's thermal
  continuum radiation has been detected; at z = 2.286, it corresponds to
  a rest wavelength of 370 microns. From the entire continuum spectrum
  we estimate a dust temperature of 80 K, and from the optically thin
  radiation at 370 microns (rest frame) we find a dust mass of 2.5 X 10^8^
  h^-2^ M_sun_. For the H_2_ mass of 1 X 10^11^ h^-2^ M_sun_ implied by
  the CO line luminosity, this yields a ratio of the mass of gas (H_2_ +
  He) to warm dust of 500, which is surprisingly normal for a galaxy at z
  = 2.3. It is the same value as observed in the central regions of nearby
  luminous galaxies that have solar metallicity. The ratio of observed CO
  and 370 microns (restframe) luminosities in 10214 + 4724, essentially
  the gas-to-dust mass ratio, is the same as in nearby galaxies. Hence,
  In this galaxy, most of the heavy elements have already been produced,
  at nearly present-day abundances.

Title: The IRAM interferometer on Plateau de Bure.
Authors: Guilloteau, S.; Delannoy, J.; Downes, D.; Greve, A.; Guelin,
   M.; Lucas, R.; Morris, D.; Radford, S. J. E.; Wink, J.; Cernicharo, J.;
   Forveille, T.; Garcia-Burillo, S.; Neri, R.; Blondel, J.; Perrigourad,
   A.; Plathner, D.; Torres, M.
Bibcode: 1992A&A...262..624G
Altcode:
  The IRAM interferometer on Plateau de Bure has three 15 m diameter
  antennas presently equipped with low noise receivers for the 80-115 GHz
  band. Baselines extend 160m north-south and 288 m east-west. There are
  two digital cross-correlators, a wide band continuum correlator and
  a narrow band spectral correlator. The instrument's high sensitivity
  is a result of its relatively large antennas.

Title: HCN in the center of the galaxy IC 342.
Authors: Downes, D.; Radford, S. J. E.; Guilloteau, S.; Guelin, M.;
   Greve, A.; Morris, D.
Bibcode: 1992A&A...262..424D
Altcode:
  We have mapped HCN(1-0) line emission from the center of the galaxy
  IC 342 with the IRAM interferometer at 2.7" resolution. By comparing
  this HCN map with other molecular line maps of similar resolution,
  we have made the first determination of molecular line ratios on a
  scale of 20 pc in a massive galaxy other than our own. In the five
  main clouds within 100 pc of IC 342's nucleus, the CO(1-0)/HCN(1-0)
  intensity ratio is 7 +/- 2 and is at least twice as high farther out in
  the mini spiral arms. In the central region, the line intensity ratios
  of ^13^CO(1-0)/HCN(1-0) and HCN(1-0)/NH_3_ are both ~ 2. We have also
  detected 3.4 mm continuum radiation near the center of the galaxy at a
  level of 27 mJy. Comparison with other maps shows the 3.4 mm continuum
  is free-free emission rather than thermal radiation by dust. The number
  of ionizing photons is similar to that in our Galactic center. Since the
  free-free continuum is associated with only one of the dense molecular
  clouds traced by the HCN, most of the molecular clouds in the center of
  IC 342 do not show any massive star formation activity. The gas in the
  molecular clouds is probably heated by turbulent dissipation rather than
  starlight. Since both the HCN(1-0) and the far IR radiation come from
  much smaller regions than the ^12^CO(1-0) the HCN is better correlated
  with the FIR radiation than is ^12^CO, but neither HCN nor CO trace
  star formation. The global L_FIR_/M(H_2_) ratio is only an indirect
  indicator of the efficiency of star formation in the center of IC 342.

Title: Optical Extinction in HII Regions and Nearby Bright Galaxies
Authors: Castles, J.; McKeith, C. D.; Greve, A.
Bibcode: 1992IrAJ...20..191C
Altcode:
  Observations with the 1.5 m telescope at ESO, Chile, and the 4.2 m
  WHT at RGO, La Palma, of galactic HII regions and three galaxies were
  made to evaluate the potential for A<SUB>upsilon</SUB> determination,
  using pairs of lines from transitions from common upper levels, and
  separated by a large wavelength interval. Spectral lines from the near
  UV to the near IR are shown to be accessible with modern blue-coated
  CCD detectors.

Title: Extinction towards 30 Doradus (LMC) derived from common upper
    level P-gamma/H-delta and P-delta/H-epsilon line ratios.
Authors: Greve, A.; Castles, J.; McKeith, C. D.
Bibcode: 1991A&A...251..575G
Altcode:
  We have used the ratios Pγ/Hδ and Pδ/H{epsilon of corresponding
  hydrogen multiplet lines (which originate from the same upper levels)
  to derive the extinction A_v_ in the direction of 30 Doradus in the LMC.

Title: Galaxy kinematics from ISIS spectra
Authors: Castles, J.; McKeith, C. D.; Greve, A.
Bibcode: 1991VA.....34..187C
Altcode:
  The ISIS spectrograph on the 4.2 m WHT was used to observe three
  galaxies NGC 2146, NGC 1569, and NGC 3034 (M82). Rotation curves
  along the major axes of these galaxies are presented. For NGC 3034,
  the rotation curve derived using the relatively new technique for
  measuring stellar motion from one of the the CaII IR triplet ( ∼8550
  Å) absorption lines is compared with those for the ionized gas motion
  measured from H<SUB>α</SUB> and [NII] (6583 Å) emission lines. The
  line splitting with slit oriented along the minor axis of NGC 3034
  covering 4 arc min. is examined.

Title: The Dense Molecular Core of ARP220
Authors: Radford, S. J. E.; Delannoy, J.; Downes, D.; Guélin, M.;
   Guilloteau, S.; Greve, A.; Lucas, R.; Morris, D.; Wink, J.
Bibcode: 1991IAUS..146..303R
Altcode:
  No abstract at ADS

Title: Structure of the disk of M 82.
Authors: Goetz, M.; Downes, D.; Greve, A.; McKeith, C. D.
Bibcode: 1990A&A...240...52G
Altcode:
  We present new observations of H, He, O, N and S emission lines and
  Hα and Na D absorption lines parallel to the major axis in the central
  region of the galaxy M 82, and derivations of the Balmer decrements and
  the visual extinction. Whereas the absorption lines trace the rotation
  curve of stars in the disk of M 82, the emission lines come from H II
  regions in the inner and outer starburst zones. These emission lines
  show two velocity components separated by 270 km s^-1^ in the central
  region, over 50" (760 pc) parallel to the major axis. We interpret the
  two velocity components as H II regions in the galactic disk (component
  I), and the starburst wind (component II). In the current picture of
  M 82, the starburst region consists of the brighter 10 micron zone
  of diameter 100 pc (+/- 5"), and extends out to the central CO zone
  of diameter 500 pc (+/- 17"). Our data show that the molecular ring
  is surrounded by a split emission line zone of diameter 760 pc (+/-
  25") near the major axis, inside of which is presumably the blowout of
  the hot superwind. The double structure in the strong emission lines
  in this zone is related to the much weaker split line system seen by
  other observers in the filaments out of the plane of M 82. Beyond this
  blowout zone is a wider, quiescent Hα zone of diameter 1500 pc (+/-
  50"), surrounded by the outer disk, whose rotation can be traced in
  stellar absorption lines.

Title: Scanning interferometer observations of the shell N 186E in
    the Large Magellanic cloud.
Authors: Rosado, M.; Laval, A.; Boulesteix, J.; Georgelin, Y. P.;
   Greve, A.; Marcelin, M.; Le Coarer, E.; Viale, A.
Bibcode: 1990A&A...238..315R
Altcode:
  The velocity field and the Hα flux of the large shell N 186E of the
  LMC are measured over a 7' x 7' field, covering most of the filamentary
  structure. The radial velocity field appears to be contamined by faint
  blue-shifted and red-shifted emission which confirms the presence of
  H I slabs along the line of sight. The remaining gas in N 186E does
  not show high velocity expansion motions (25 km s^-1^), much less
  than found inside the similar but smaller bubble N 185. The recently
  detected exciting sturs are sufficient to explain the ionization of N
  186E, although none of them is located close to the centre. The density
  inside the filaments is produced by weak shocks, where as the circular
  shape and the size of the shell indicate homogeneity of the preshock
  material, An intense interaction is found at the dense border between
  N 186E and the young neighbouring SNR, N 186D. N 186E is probably an
  old SNR, now being ionized by internal stars.

Title: Dust in emission nebulae of the LMC derived from photometric
    reddening of stars.
Authors: Greve, A.; van Genderen, A. M.; Laval, A.
Bibcode: 1990A&AS...85..895G
Altcode:
  We present VBLUW photometric observations of stars in emission nebulae
  of the LMC (N 4AB, N 11AB, N 12, N 48ACB, N 57C, N 77, N 79ABDE, N 81,
  N 83AB, N 163, N 195, N 214C, 30 Dor). The luminosities and extinctions
  A_v_ of the stars are derived. We find agreement between the average
  photometric extinction of the nebulae and the extinctions derived
  from the Balmer line decrement measured by Caplan and Deharveng (1985,
  1986). The photometric extinction, are shown in the CO map of the LMC
  (Cohen et al, 1988).

Title: CCD spectroscopy of P<SUB>γ</SUB>(10939),
    P<SUB>δ</SUB>(10049) and corresponding Balmer lines in 30 Doradus.
Authors: Greve, A.; McKeith, C. D.; Castles, J.
Bibcode: 1989Msngr..57...56G
Altcode: 1989Mgr....57...56G
  Understanding the physical and dynamical evolution of galactic and
  extragalactic H11 regions requires a knowledge of the dust component
  and its distribution. To date the extinction Av has been derived by
  various methods: optical and infrared line ratios, comparison of radio
  and emission line fluxes, stellar photometry, etc. In particular the
  intensity ratios of the strong and spectroscopically easily accessible
  Balmer lines Halpha, Hbeta are frequently used to derive Av via their
  decrement. Since these lines originate from different upper levels, the
  interpretation of the observed line ratios requires recombination line
  model calculations (cf. Osterbrock 1974) which in many extragalactic
  cases have failed to give consistent results (Ward et al. 1987, Malkan
  1983, Rieke and Lebofsky 1981). This difficulty can be avoided by
  using multiplet line ratios originating from the same upper level so
  that the theoretical line ratios depend primarily on their relative
  transition probabilities.

Title: The Swedish-ESO submillimeter telescope (SEST).
Authors: Booth, R. S.; Delgado, G.; Hagstrom, M.; Johansson, L. E. B.;
   Murphy, D. C.; Olberg, M.; Whyborn, N. D.; Greve, A.; Hansson, B.;
   Lindstrom, C. O.; Rydberg, A.
Bibcode: 1989A&A...216..315B
Altcode:
  The Swedish-ESO 15 m diameter, submillimetre wavelength telescope on
  La Silla is now complete. Here we describe the salient features of
  the telescope and the first instrumentation as well as results from
  commissioning tests. The telescope reflector surface has been set
  within 65 microns of the ideal paraboloid and the aperture efficiency
  at 100 GHz is about 60%. A pointing accuracy of approximately 3" rms
  has been measured in both azimuth and elevation. Results of the first
  astronomical measurements are presented.

Title: Extinction towards the Orion nebula derived from
    P-gamma/H-delta and SII 1.04 mu-m/4071 A line ratios.
Authors: Greve, A.; Goetz, M.; McKeith, C. D.; Barnett, E. W.
Bibcode: 1989A&A...215..113G
Altcode:
  Using the Orion nebula as typical example of H II regions, it is
  demonstrated that the differential extinction can be derived precisely
  from (P-gamma)/(H-delta) and forbidden S II blue and IR line ratios
  observed with long-slit CCD spectroscopy. This spectroscopic imaging
  technique allows a correct elimination of perturbing atmospheric sky
  emission lines in the IR wavelength region, so that this technique
  may become a useful diagnostic tool for other H II regions.

Title: Study of Bubbles in the Large Magellanic Cloud
Authors: Laval, A.; Rosado, M.; Boulesteix, J.; Georgelin, Y. P.;
   Marcelin, M.; Cahalo, D.; Greve, A.; Larsen, J.; Viale, A.
Bibcode: 1989rdmc.conf..151L
Altcode:
  No abstract at ADS

Title: Interaction between a stellar wind and the ionized gas in N120
    (LMC)
Authors: Laval, A.; Rosado, M.; Boulesteix, J.; Georgelin, Y. P.;
   Marcelin, M.; Greve, A.; Larsen, J.; Viale, A.
Bibcode: 1989LNP...350..194L
Altcode: 1989IAUCo.120..194L; 1989sdim.conf..194L
  No abstract at ADS

Title: An investigation of the micro variations of highly luminous
    OBA type stars (alpha Cygni variables). VII. The two interacting O
    type eclipsing binaries UW CMa = HD 57060 and 167971.
Authors: van Genderen, A. M.; van Amerongen, S.; van der Bij, M. D. P.;
   Damen, E.; van Driel, W.; Greve, A.; van Heerde, G. M.; Latour, H. J.;
   Ng, Y. K.; Oppe, J.; Wiertz, M. J. J.
Bibcode: 1988A&AS...74..467V
Altcode:
  VBLUW photometry of two interacting O type binaries UW CMa and HD
  167971 are presented and discussed. The light and colour curves of
  UW CMa (P = 4<SUP>d</SUP>.39336) show evidence of plasma streams in
  the system. The light amplitude of the optical micro variations likely
  originating mainly on the O8.5 I component, is about twice as large as
  for non distorted stars of the same temperature. The micro variations
  superimposed on the light curve of HD 167971 (P = 3<SUP>d</SUP>.3218),
  likely originating on the more distant component of this triple system,
  are of a normal size. Convincing colour variations during the binary
  revolution are detected. The size of these amplitudes are corrected
  for the light of the companion(s).

Title: Photometric reddenings of stars in emission nebulae of the
    MagellanicClouds.
Authors: Greve, A.; van Genderen, A. M.; Laval, A.; van Driel, W.;
   Prein, J. J.
Bibcode: 1988A&AS...74..167G
Altcode:
  We present VBLUW observations of stars in emission nebulae of the SMC
  (N 66, N 83, N 90) and the LMC (N8, N9, N 11E, N23, N43, N48, N59, N84,
  N 148, N 159, N 160A, N 185, N 186). The stellar population (colour
  indices, luminosities) and the extinction in the central regions of
  the nebulae are derived. We find several stars, in particular in N
  159 and N 160A, with extinctions A_V_ &gt; 1.5 mag. Intrinsically more
  luminous, hence more massive, stars, or groups of stars, are located
  in the regions of the highest extinction.

Title: Thermal control of the IRAM 30-m millimeter radio telescope
Authors: Baars, J. W. M.; Hooghoudt, B. G.; Greve, A.; Penalver, J.
Bibcode: 1988A&A...195..364B
Altcode:
  The performance of millimeter wavelength telescopes may be critically
  impaired by temperature differences, which cause structural
  deformations larger than those due to gravity and wind. Model
  calculations show that a temperature uniformity of the telescope
  structure of about 1 K is required. For the 30-m millimeter radio
  telescope that is realized by thermal insulation of the telescope
  and temperature control of the reflector support structure and the
  quadrupod, allowing full performance independent of time of day or
  season. A description of the control system is given together with
  measured performance data. The additional cost of the thermal control
  amounts to 10 percent of the total cost of the telescope. The increase
  in availability with unimpaired characteristics is estimated at a
  factor of 1.5-2. Calculations with a detailed thermal model are also
  in accordance with the measurements. Thus temperature effects can be
  included numerically in the structural design and be controlled to
  eliminate thermally induced deformations.

Title: The Swedish-ESO Submillimeter Telescope (SEST)
Authors: Booth, R. S.; Delgado, G.; Hagstroem, M.; Johansson, L. E. B.;
   Murphy, D. C.; Olberg, M.; Whyborn, N. D.; Greve, A.; Hansson, B.;
   Lindstroem, C. O.
Bibcode: 1988STIN...8927605B
Altcode:
  The Swedish-ESO Submillimeter Telescope (SEST) is a 15 m telescope,
  which can operate at wavelengths down to 0.8 mm, built on the European
  Southern Observatory (ESO) site of La Silla, in the Chilean Andes, at
  an altitude of 2300 m. It is the only large submillimeter telescope in
  the Southern Hemisphere. The main technical features of the telescope
  and observing system, and the results of the commissioning tests by
  the team in Chile are described. The telescope reflector surface has
  been set within 65 micrometers vms of the ideal paraboloid, and the
  aperture efficiency at 100 GHz is about 60 percent.

Title: Solar Flux Spectra at 2000-3000 a High Resolution
Authors: Greve, A.
Bibcode: 1988iue..prop.3255G
Altcode:
  No abstract at ADS

Title: VBLUW photometry of emission nebulae.
Authors: Greve, A.; van Genderen, A. M.
Bibcode: 1987A&A...174..243G
Altcode:
  Observed VBLUW colours of emission nebulae of the SMC, LMC, and the
  Orion nebula are reconstructed from published emission line ratios
  and theoretical H and 2-photon continua. The authors discuss colour
  corrections for internal reddening, scattered star light (in particular
  for the Orion nebula), and stellar backgrounds. The calculations
  reproduce the observed colours in the (B-U)/(B-L) diagram and indicate a
  correlation of (B-U) with the [O II] 3727/Hβ line ratios. After a more
  detailed empirical confirmation, this correlation may eventually be
  used as a diagnostic indicator of emission nebulae. The authors also
  give colours for a few galactic planetary nebulae, and a tentative
  interpretation of the measurements.

Title: The stars and gas in the region of N 63 A (LMC).
Authors: Laval, A.; Greve, A.; van Genderen, A. M.
Bibcode: 1986A&A...164...26L
Altcode:
  N 63A is located in the cluster NGC 2030 of the LMC. From VBLUW
  observations of some cluster stars the authors derive A<SUB>V</SUB> =
  0.6 mag reddening in the direction of N 63A; the age of the cluster is
  estimated as ≡4×10<SUP>6</SUP>yr. VBLUW observations indicate the
  western knot of N 63A to be excited by an 05-9 main sequence star. The
  north-eastern and southern knots form the known SNR. Fabry-Perot
  observations indicate a velocity range of 100 - 300 km s<SUP>-1</SUP>
  for the SNR gas.

Title: VBLUW photometry of solar-type stars.
Authors: Greve, A.; van Genderen, A. M.
Bibcode: 1986A&A...160..392G
Altcode:
  VBLUW photometric observations of 35 solar-type stars are presented
  and discussed in terms of abundance, T<SUB>eff</SUB> and gravity
  (log g). Using the empirical transformation between the VBLUW and UBV
  systems, for four stars being very similar to the sun the authors derive
  (B-V) = 0.656±0.011.

Title: Reflector surface measurements of the IRAM 30-m radio telescope
Authors: Greve, A.
Bibcode: 1986IJIMW...7..121G
Altcode:
  Surface measurements of the IRAM 30 m radio reflector made with a
  theodolite-laser-tape system are described. The results obtained with
  this survey system agree with holography measurements made at 22 GHz
  (Morris 1985).

Title: Solar Flux Soectra at 2000-3000 Angstrom, High and Low
    Resolution
Authors: Greve, A.
Bibcode: 1986iue..prop.2715G
Altcode:
  No abstract at ADS

Title: VBLUW photometry of the stars and nebulosity of N 70 in
    the LMC.
Authors: Greve, A.; van Genderen, A. M.
Bibcode: 1985A&A...148..397G
Altcode:
  Photometric VBLUW data are given for the stars and nebulosity of N 70
  in the LMC. The data for the central cluster stars, an OB association
  mainly of main sequence stars, confirm earlier color determinations
  and spectral types. Located in the direction of the shell region of the
  nebula, a number of supergiants which may partly be associated with N
  70 are found. The photometry for three of these stars give extinctions
  of A(VJ) = 3m. Also found for a few stars in other nebulae of the LMC,
  this amount of extinction - if of interstellar origin - does not agree
  with the interstellar gas to dust ratio of the LMC. The extinction
  may be produced in circumstellar dust shells.

Title: Status report on the IRAM 30-m telescope.
Authors: Thum, C.; Morris, D.; Greve, A.
Bibcode: 1985ESOC...22...57T
Altcode: 1985sma..work...57T
  Apart from commissioning the new SIS receivers and the bolometer, the
  technical activities for the rest of this year include derivation of
  a pointing model at high frequencies. Further work includes tests of
  switching techniques and an extension of the data reduction software and
  documentation. From September onward, the telescope will be scheduled
  50 per cent of the time for visitor programs which, for the time being,
  have to originate from the IRAM member countries (90 per cent) or from
  the telescope host country, Spain (10 per cent).

Title: Photometry of AO 0538-66 during an active and subsequent
    inactive state.
Authors: van Paradijs, J.; van Amerongen, S.; de Kool, M.; Pakull,
   M.; Deul, E. R.; Lub, J.; Greve, A.
Bibcode: 1984MNRAS.210..863V
Altcode:
  The authors present the results of photometric observations of the
  optical counterpart of the recurrent X-ray transient A0538-66. Three
  outbursts were observed in 1982 April and May. During the period 1982
  October - 1983 February the source did not show outbursts. Combining
  their data with those of Densham et al. the authors find evidence for
  a secular decrease of the size of the outbursts throughout a period of
  activity. The interoutburst UBV properties of A0538-66 likewise show a
  progressive change. During the off-state A0538-66 shows small-amplitude
  variability, similar to that observed in some 'normal' Be stars. In the
  (V, B-V) and (U-B, B-V) diagrams both these variations and the secular
  variations of the previous interoutburst data lie along tracks which
  appear to be connected.

Title: Observations of the emission nebulae S 188 and S 274 at 2.7
    and 5 GHz.
Authors: Salter, C. J.; Greve, A.; Weiler, K. W.; Birkle, K.;
   Dennefeld, M.
Bibcode: 1984A&A...137..291S
Altcode:
  The two morphologically similar nebulae S188 and S274 have been mapped
  in the radio continuum at 2.7 and 5 GHz. The sources seem to have
  thermal spectra and the new data effectively rule out that either
  or both are shell-type supernova remnants. It is demonstrated that a
  number of distance-independent parameters of the nebulae are closely
  similar and all present evidence indicates that both are old planetary
  nebulae. On this hypothesis, the distances of the nebulae are estimated
  from the radio data. A number of other parameters of the objects are
  considered in the light of these distances.

Title: Comparison of Ultraviolet Spectra from Solar Type Stars
Authors: Greve, A.; Wamsteker, W.
Bibcode: 1984SoPh...94....3G
Altcode:
  We compare high-resolution spectra from the Sun and the four solar-type
  stars 16 Cyg A, 16 Cyg B, HD 32008, HD 34411 obtained with IUE in
  the wavelength range 2650-2930 Å. The comparison is made for peak
  intensities between absorption lines. At the level of accuracy of
  the IUE observations, the stars 16 Cyg A, 16 Cyg B, HD 34411 are
  indistinguishable from the Sun, in particular the MgII resonance line
  profiles are identical. HD 32008 is not a solar analog but is evidently
  of late G to early K spectral type.

Title: A Cassegrain type null-corrector for surface tests of parabolic
    microwave reflectors
Authors: Greve, A.
Bibcode: 1984IJIMW...5..761G
Altcode:
  The design of Cassegrain-type interferometric null-correctors for
  steep parabolic reflectors (as used for microwave and IR observations)
  is examined analytically. The optical principle is explained and
  illustrated, and the surface contour is derived. It is demonstrated
  that physically meaningful solutions exist, and the practicality of a
  device using metallic aspheric surfaces and 10.6-micron light from a
  CO2 laser is discussed. Surface roughness less than about 1.5 microns
  rms and accuracy about 1 mm are required.

Title: Prediction of wet air refraction at microwaves (research note)
Authors: Greve, A.
Bibcode: 1984IJIMW...5..315G
Altcode:
  Radiosonde data have been used to calculate the actual wet air
  refraction which results from the combined effect of the dry air and
  water vapor components, in an attempt to establish, for long periods and
  large seasonal changes, correlations with atmospheric qualities that
  are measurable at the surface. Attention is given to the possibility
  of wet air refraction prediction on the basis of surface pressure
  and temperature measurements, integrated water vapor, and microwave
  atmospheric emission data.

Title: Atmospheric water vapour measurements at Zelenchukskaya
    (U.S.S.R.) and La Silla (Chile).
Authors: Sherwood, W. A.; Schultz, G. V.; Greve, A.
Bibcode: 1983InfPh..23..109S
Altcode:
  Direct measurements of atmospheric precipitable water vapour are
  presented for Zelenchukskaya at the site of the 6 m telescope. The data
  may be compared with previous data and with indirect determinations
  based on extinction measurements at 1 mm interpreted in terms of
  experimental water vapour transmittance measurements. It is shown
  that the cosecant law is justified in practice. Indirect measurements
  of water vapour at the European Southern Observatory, La Silla show
  that precipitable water vapour may be less than 2 mm for ≡50% of the
  southern hemisphere winter time. A low value of 0.6-0.7 mm is reported.

Title: Correlation of surface humidity and integrated atmospheric
    water vapour determined from infrared measurements.
Authors: Greve, A.
Bibcode: 1983InfPh..23...59G
Altcode:
  For four European mountain sites the author correlates values
  of precipitable water vapour with simultaneous data on surface
  humidity. For the particular sites, the correlation of daily values
  is too poor to allow reliable predictions of water vapour required
  for astronomical observations.

Title: Absolute photometry of the Crab Nebula
Authors: Greve, A.; van Genderen, A. M.
Bibcode: 1982A&A...115...79G
Altcode:
  The observations discussed were made on December 6 and 7, 1980,
  using the Walraven VBLUW simultaneous photometer with the Leiden
  90-cm light collector (ESO, La Silla, Chile). For each observation,
  a 16-arcsec diaphragm was used, and the integration time was 192 s. The
  astrophysical quantities derived for M 1 from the broad passband VBLUW
  observations are found to agree with other observations. This agreement
  is believed to derive from a determination of the contribution of
  emission line radiation in the observations. It is pointed out that
  the photometric system may be used to observe, with smaller diaphragms
  (greater than about 5 arcsec), small-scale details of M 1, for example,
  the synchrotron emission of the wisps and the line emission at positions
  where spectral data are given by Woltjer (1958).

Title: Determination of the atmospheric water vapour content above
    La Silla and the prospects for FIR observations
Authors: Sherwood, W. A.; Greve, A.
Bibcode: 1982esoi.work..173S
Altcode:
  The results of a survey to estimate the amount and effects of
  precipitable water vapor (pwv) are reported, with an emphasis on
  the influence on FIR observations. The measurements were made at La
  Silla for 24 hr/day for nine days in July 1981. An increase in pwv
  was detected only once during daytime, and when rises were observed
  the temperature was low; pwv and humidity were once seen to decrease
  simultaneously. Use of a 350 micron filter encountered an atmospheric
  transmissivity of 34 percent. Standard planets were used to calculate
  the extinctions due to the water vapor strengths in the IR. The
  implementation of 24 hr/day monitoring of pwv with an IR hygrometer is
  recommended to permit transferring observations to lower wavelengths
  in the presence of a dryer atmosphere.

Title: Book reviews
Authors: Page, D. E.; Pick, M.; Kresák, L.; Reijnen, G. C. M.;
   Cameron, A. G. W.; Schuurmans, Cornelius J. E.; Ya Marov, Mikhail;
   Goldberg, B.; Kaiser, T. R.; Lemaire, J.; Sehnal, L.; Elsässer,
   H.; Valniček, B.; de Graaff, W.; Pacini, Franco; Rohlfs, K.; de
   Landtsheer, A. C.; Zhongolovich, I. D.; de Jager, C.; Greve, A.;
   Ruprecht, J.; Tayler, R. J.; Kockarts, G.; Axford, W. I.; Tabor, H.;
   Bolle, H. J.; Kaldis, E.; Reijnen, Gijsbertha C. M.; De Loore, C.;
   Kleczek, J.; Murray, C. A.; Wallenquist, Åke
Bibcode: 1981SSRv...28..105P
Altcode:
  No abstract at ADS

Title: Metrology of the Effelsberg 100 meter radio reflector.
Authors: Greve, A.
Bibcode: 1981ZVer..106..308G
Altcode:
  No abstract at ADS

Title: Quality evaluation of radio reflector surfaces
Authors: Greve, A.; Hooghoudt, B. G.
Bibcode: 1981A&A....93...76G
Altcode:
  Three rms values of sigma:sigma<SUB>n</SUB> were considered to
  represent the geometrical quality of the surface for the evaluation of
  radio reflector surfaces. The effective rms-value sigma<SUB>TP</SUB>
  represents the electrical quality of the reflector; this quantity and
  the corresponding surface weighting function must be taken into account
  in design calculations, adjustment procedures, and in comparisons with
  the radio gain measurements. The Effelsberg 100 m antenna is used as
  an example of a steep parabolic reflector.

Title: Supernova Remnants in the LMC and SMC
Authors: Greve, A.
Bibcode: 1981iue..prop..882G
Altcode:
  No abstract at ADS

Title: Book Review - Radio Recombination Lines
Authors: Shaver, P. A.; Greve, A.
Bibcode: 1981SSRv...28..112S
Altcode:
  No abstract at ADS

Title: Modulated laser surface surveying system for mm-wavelength
    radio telescopes.
Authors: Greve, A.; Harth, W.
Bibcode: 1981SPIE...36..110G
Altcode:
  For high precision (50 micron) surface measurements of a mm-wavelength
  radio reflector we have developed a modulated laser (He-Ne 632 nm,
  mod. freq. 1.7 GHz) distance ranger and an angular measuring system
  of 0.4" accuracy. We give test results of the system.

Title: UV Opacities of Solar-Type Stars
Authors: Greve, A.
Bibcode: 1981iue..prop..881G
Altcode:
  No abstract at ADS

Title: Astrophysical interpretation of the lam lam 1200-7300
    angstrom emission line spectrum of a filament in the CYG Loop
    Supernova remnant.
Authors: Dodorico, S.; Dennefeld, M.; Benvenuti, P.; Dopita, M. A.;
   Greve, A.
Bibcode: 1980A&A....92...22D
Altcode:
  An IUE spectrum of a filament in the Cygnus Loop supernova remnant
  obtained with the low resolution, long wavelength camera, has been
  combined with earlier far UV and optical data to obtain a complete
  spectral coverage between 1200 and 7350 Å. The observed continuum is
  fully understood as a combination of free-free emission, recombination
  and hydrogen two photon emission, reinforced by collisional excitation
  to the 2S½ level. <P />The emission lime spectrum is, in general, well
  interpreted in the framework of a shockwave model of moderate velocity
  (v<SUB>s</SUB>=90 km/s) and depleted abundances. <P />The unexpected
  weakness of the C II λ1335 Å line may be due to scattering in the
  filament seen as an edge on sheet, or, less likely, owing to absorption
  in the intervening interstellar medium, indicates a column density
  of interstellar C II of ≃2.5 × 10<SUP>14</SUP> cm<SUP>-2</SUP>
  toward the remnant.

Title: The formation of the Mg II resonance line wings in the solar
    atmosphere (II).
Authors: Greve, A.
Bibcode: 1980A&A....90..231G
Altcode:
  Synthetic LTE profiles of the Mg II resonance lines computed for
  the HSRA, VAL, and 'Ca II and Mg II' model atmospheres are compared
  with profiles of the average quiet sun in the gamma wavelength range
  2760-2820 A at the radial positions of 1.0, 0.6 + or - 0.06, and 0.43 +
  or - 0.01. The expression for the total opacity as a function of the
  height is derived; these opacity functions reproduce the observed
  local continuum intensities at gamma 2660 and 2940 and the adopted
  wavelength averaged limb darkening curve. The most appropriate value
  of the abundance of Mg and the factor applied to the collisional
  broadening is derived from the best fit of the calculated profiles;
  the comparison of the computed and observed profiles shows that none
  of the one-component static model atmospheres for the average quiet
  sun reproduces the center-to-limb variations for the central parts of
  the MG II profiles.

Title: Absolute fluxes, equivalent width and centre-to-limb profiles
    of the solar Mg II resonance lines (I).
Authors: Greve, A.; McKeith, C. D.
Bibcode: 1980A&A....90..224G
Altcode:
  For the average quiet Sun we derive from high resolution Fabry
  Perot-echelle spectrograms profiles of the Mg II resonance lines
  in the wavelength region 2760 Å ≲ λ ≲ 2820 Å for the radial
  positions 1.0 ≧ = μ ≧ 0.995, 0.60±0.06 and 0.43±0.10. The
  profile of a plage region near the disc centre is also presented. <P
  />From the absolute flux calibrated observations of Kachalov and
  Jakovleva (1962), and Tousey et al. (1974), we derive the Mg II flux
  profile in the wavelength region 2660 Å ≲ λ ≲ 2940 Å. The
  Minnaert-Houtgast method is applied to the far wings of this profile
  in order to determine the undisturbed continuum level. Related to
  this continuum the equivalent width of the Mg II resonance lines is
  83 Å. <P />For the region 2770 Å ≲ λ ≲ 2820 Å a wavelength
  averaged limb darkening curve is derived. The Mg II profiles are
  calibrated using a combination of this limb darkening curve and the
  low spectral resolution flux profile. Our profile for the disc centre
  agrees in shape and absolute intensity with Kohl and Parkinson's
  (1976) recent observation. <P />In the Appendix we generalize the
  Minnaert-Houtgast method for a blend of two strong multiplet lines
  and a linear variation of the continuum intensity.

Title: Methods for the analysis of stellar spectra veiled by lines
    (III).
Authors: Greve, A.; Zwaan, C.
Bibcode: 1980A&A....90..239G
Altcode:
  UV spectrograms of the sun and of Alpha CMi are analyzed to investigate
  the effects of finite spectral resolution in the interpretation
  of stellar spectra veiled by lines. The recorded completeness of
  intrinsic spectral detail is examined by means of the ruggedness
  parameter of Ivanov and Salman-Zade (1976). Solar spectrograms of
  approximately 0.03 A resolution are a good representation of the true
  spectral distribution. The power of the Minnaert-Houtgast method for
  tracing line wings and establishing the local 'continuum' background
  in spectra crowded with lines is demonstrated.

Title: Strehl number degradation by large-scale systematic surface
    deviations.
Authors: Greve, A.
Bibcode: 1980ApOpt..19.2948G
Altcode:
  For the particular case of circular zones, the corresponding image
  degradation is derived. The equations obtained lead to a general
  expression for the on-axis intensity of the degradation image, i.e.,
  the Strehl number, for large-scale surface deviations (SD). Random
  deviations (RD) are compared with SD. It is shown that the quasi-rms
  value of SD has the same optical significance as the rms value of RD.

Title: The Influence of Spectral Resolution on Line Blending and
    Wavelength Positions in the Solar Ultraviolet Spectrum
Authors: Greve, A.; McKeith, C. D.
Bibcode: 1980SoPh...65..405G
Altcode:
  For representative sections of the solar UV spectrum (λ 2765 Å-λ
  2790 Å, λ 2765 Å-λ 2805 Å) the line density and the accuracy of
  wavelength positions of absorption features are derived as function
  of the spectral resolution. In low resolution spectrograms unresolved
  blends may shift intrinsic wavelength positions of absorption lines
  by amounts up to a few tenths of the spectral resolution.

Title: On the Zeeman splitting of high N recombination lines
Authors: Greve, A.; Pauls, T.
Bibcode: 1980A&A....82..388G
Altcode:
  The Zeeman splitting pattern of high-n alpha and beta lines of H II,
  He II, and Cu II ions is calculated rigorously. All allowed transitions
  are taken into account, together with the corresponding strengths for
  Russel-Saunders coupling, and the allowed fine structure transitions,
  the corresponding Lande factors, and the strengths are obtained by the
  application of selection rules. It is found that for principle quantum
  numbers between 30 and 300, identical hydrogen-like Zeeman triplets are
  obtained for the alpha and beta lines of the three ions, with a Lande
  factor generally equal to 1 and triplet components of equal strength.

Title: On the hyperfine structure of the mesospheric water vapour line
    (22 GHz).
Authors: Greve, A.
Bibcode: 1978JATP...40.1029G
Altcode:
  Model calculations of the hyperfine structure splitting of the
  mesospheric water vapor line at 22.2351 GHz are examined. While
  the vapor line was observed with the 120-ft Haystack antenna in
  conjunction with a cooled ruby maser, it is suggested that detection
  of the hyperfine structure splitting will be extremely difficult
  unless the constitution of the atmosphere deviates considerably at
  high altitudes from presently accepted models. Hyperfine structure
  calculations for two mixing ratios are presented. The mesospheric
  water vapor line, seen in emission and absorption against the sun,
  has a typically pressure-broadened profile.

Title: Further evidence for downflow in the solar atmosphere.
Authors: Greve, A.
Bibcode: 1978SoPh...58..287G
Altcode:
  Downflow velocities of the higher atmospheric layers of the Sun are
  derived from wavelength measurements of the Mg II core absorption.

Title: Off-axis aberration of achromatic Schmidt correctors.
Authors: Greve, A.
Bibcode: 1978Optik..50..235G
Altcode:
  No abstract at ADS

Title: The water vapour content in the western European atmosphere
    obtained from infrared measurements.
Authors: Greve, A.
Bibcode: 1978InfPh..18..127G
Altcode:
  We report on measurements of the water vapour content in the western
  European atmosphere obtained from infrared attenuation measurements,
  made during a site survey for a millimetre-wave radio observatory.

Title: Achromatic Schmidt corrector plates for the near infrared.
Authors: Greve, A.
Bibcode: 1978InfPh..18....7G
Altcode:
  The paper demonstrates the advantages of near infrared achromatic
  Schmidt systems, which eliminate spherical aberration at two
  wavelengths, and give a residual spherical aberration which fulfils
  the Strehl/Rayleigh criterion. The theory is illustrated by a few
  numerical examples.

Title: The ultraviolet solar spectrum 2756Å - 2831Å - Identification
    of absorption lines
Authors: Greve, A.; McKeith, C. D.
Bibcode: 1977A&AS...30..387G
Altcode:
  A list of atomic spectral lines and semi-empirical gf values published
  by Kurucz and Peytremann (1975) allows increased and improved
  identifications of solar UV absorption lines previously observed in
  the range 2756 1 A. The compiled table of identifications with listed
  gf values and excitation potentials is relevant to line blanketing
  estimates in model atmosphere calculations of late-type stellar
  spectra. Key words: solar UV spectrum - identifications

Title: Absolute photometry of the supernova remnants N 49 and N 64
    A in the Large Magellanic Cloud.
Authors: Greve, A.; van Genderen, A. M.
Bibcode: 1977A&A....59..267G
Altcode:
  Summary. We present five-colour photometric (Walraven system)
  observations of the supernova remnants N 49 and N 63 A of the Large
  Magellanic Cloud. The observations of N 49 indicate an optically thin,
  filamentary shell. The photometric observations allow a calibration
  of the spectroscopic observations of N 49, published by Osterbrock and
  Dufour (1973); absolute surface intensities of the spectral lines can
  be derived. A detailed comparison of the observations of N 49 with
  predictions from shock wave models is made and good agreement is
  found. As a particular conclusion, the interstellar medium density
  near N 49 is found to be . Key words: supernova remnants photometry
  absolute spectral line intensities shock wave model

Title: High n solar radio recombination lines.
Authors: Greve, A.
Bibcode: 1977SoPh...52..423G
Altcode:
  For a representative set of atmospheric and atomic parameters we
  determine the strengths of solar dielectronic recombination lines
  originating in ions with Z ⩽ 6 at frequencies of ≳70 GHz. We
  compare the line strengths derived here with those calculated by
  Berger and Simon (1972) and find that our values for representative
  ions with Z≲3 are lower by a factor 10<SUP>2</SUP>-10<SUP>3</SUP>,
  being mainly the result of the inclusion of the electronic pressure
  broadening. We outline the requirements for the detection of lines,
  which must establish an upper limit of at least ≈10<SUP>-5</SUP>
  for the line to continuum ratio.

Title: Die Justierung der Reflektorflächen großer Radioteleskope.
Authors: Greve, A.
Bibcode: 1977S&W....16..122G
Altcode:
  The importance of an accurate agreement of the characteristics
  of the actual reflector surface with the properties of the ideal
  surface in the case of optical and radio telescopes is considered. The
  obtainable surface quality of the reflectors of optical telescopes and
  the methods used for testing the surface characteristics are briefly
  discussed. A description is given of the procedures which can be used
  for a correction of the surface characteristics of the aluminum-steel
  reflectors of radio telescopes. The required mathematically defined
  surface characteristics are obtained with the aid of approaches
  involving the adjustment of the sectional elements. Advantages and
  drawbacks of the various available methods are evaluated.

Title: The Brightness Distribution over the Moon's Disk at 6 cm
    Wavelength
Authors: Hirth, W.; Butz, M.; Fuerst, E.; Greve, A.
Bibcode: 1976Moon...15..317H
Altcode:
  On November 27, 1974, a map of the Moon was obtained at 6 cm wavelength
  with the 100-m-telescope in Effelsberg. The high angular and favourable
  temperature resolution allowed an interpretation of the observed
  brightness distribution. The dominant feature of the brightness
  distribution is the centre-to-limb variation, particularly noticeable
  in the direction of the poles. The exponentα of the commonly adopted
  cos<SUP> α </SUP> (ψ)-law, describing the temperature variation
  across the lunar disk, is determined asα ≃ 0.4. The North-South
  variation of the lunar surface temperature is estimated to be 30%;
  the depth of penetration (L <SUB>e</SUB>) of electromagnetic waves of
  6 cm wavelength is found to beL <SUB>e</SUB> ≃ 17 m.

Title: Fluorescence lines excited by the Mg II resonance lines (II).
Authors: Greve, A.
Bibcode: 1976A&A....51..313G
Altcode:
  The influence of spectral resolution on the full width at the base
  of the emission core of the Mg II k line (2795.5 A) is determined
  by comparing solar observations with convolved profiles, and a
  width-magnitude relation is derived. The relation is used to predict
  the behavior of fluorescence lines excited by Mg II emission cores in
  Ke, Me, and N stars.

Title: Achromatic Schmidt corrector plates.
Authors: Greve, A.
Bibcode: 1976OptLT...8..137G
Altcode:
  Two types of achromatic Schmidt corrector plate are described; both
  give an on-axis Strehl number S ⪆ 0.8 over an extended wavelength
  region. It is found that this specification can only be achieved
  by combining a positive and a negative plate and by restricting the
  speed ratio D/N<SUP>3</SUP> of the system. The theory is illustrated
  by numerical examples.

Title: The Zeeman Broadening of High n Solar Recombination Lines
Authors: Greve, A.
Bibcode: 1975SoPh...44..371G
Altcode:
  The Zeeman broadening of high n lines is derived. While in areas of
  the quiet Sun with field strengths of ≈1 G the upper boundary of
  the observable frequency region of recombination lines is defined by
  electron impact broadening, in active regions with field strengths
  ≳25 G the Zeeman broadening will shift this boundary to higher
  frequencies. The frequency region most favourable for observations
  is derived and the corresponding Doppler, electron impact and Zeeman
  broadening are discussed. The strengths of the recombination lines
  obtained in earlier calculations is reduced when one considers besides
  the Doppler broadening the electron impact and Zeeman broadening
  also. The frequency region favourable for observations is compared
  with the atmospheric transparency of the microwave region; it is
  found that observations require at least high altitude stations or
  space-based platforms. Details of using the Zeeman broadening of high
  n recombination lines for mapping (coronal) magnetic fields are given.

Title: Schmidt systems for the near-infrared.
Authors: Greve, A.
Bibcode: 1975InfPh..15..239G
Altcode:
  The formulae which define the parameters (focal ratio, field) of
  a seeing-limited Schmidt system are given. Near-infrared (5000 to
  15,000 A) Schmidt systems are discussed for nine different corrector
  plate materials.

Title: High n Emission and Absorption Lines of the Sun (II)
Authors: Greve, A.
Bibcode: 1975SoPh...40..329G
Altcode:
  Considering the electronic pressure broadening of highn solar
  recombination lines, an upper wavelength limit of the observable
  region of possible lines is derived. The reason that no lines have
  been observed is discussed.

Title: Eine semiempirische Entfaltungsmethode an scharfen Gradienten
    einer Strahlungsflußverteilung
Authors: Butz, M.; Greve, A.; Hachenberg, O.; Hirth, W.
Bibcode: 1975MitAG..36..116B
Altcode:
  Problems regarding the discussion of errors occur when a deconvolution
  approach utilizing the Fourier transform or other methods is
  employed in the case of sharp gradients. A description is given of a
  semiempirical method for which an evaluation of the error can be more
  easily performed. The method involves a comparison of the measured
  flux distribution with the flux distribution obtained in the case of
  the convolution of an ideal box-like brightness distribution.

Title: Achromatic Schmidt corrector plates.
Authors: Greve, A.
Bibcode: 1975Optik..42...87G
Altcode:
  No abstract at ADS

Title: Fluorescence lines excited by the Mg II resonance doublet.
Authors: Greve, A.
Bibcode: 1974A&A....36..135G
Altcode:
  Summary. Possible fluorescence lines, excited by absorption lines
  coinciding with the Mg n resonance line emission, are listed. We point
  out that two further absorption lines of Fe I and Zr I may possibly
  affect the shape of the Mg ii 2795.52 A line of oc ORI, since in the
  visible spectrum of Ke, Me and N stars a fluorescence counterpart of
  these lines is observed with reasonable strength. Key words: stellar
  Mg II emission - fluorescence lines

Title: The ultraviolet solar spectrum 2756 Å 2831 Å
Authors: Greve, A.; McKeith, C. D.
Bibcode: 1974SoPh...37....3G
Altcode:
  The ultraviolet spectrum of the Sun over the region 2756 Å to 2813 Å
  has been observed with a spectral resolution of 0.016 Å during the
  rocket flight of an interferometer spectrograph. Reduced wavelengths
  and identifications are presented together with a spectral atlas of
  the recorded region.

Title: High n Emission and Absorption Lines of the Sun
Authors: Greve, A.
Bibcode: 1974SoPh...36...85G
Altcode:
  Due to the expected peaks of the b<SUB>n</SUB> curves of ions in the
  chromosphere-corona transition region and the corona, high n transition
  lines change from emission to absorption in the wavelength region from
  ≈ 1/2 mm for elements in a low state of ionization, to ≈ 2 mm for
  elements in a high state of ionization. The observational consequences
  are discussed. We believe that lines have not yet been found because
  the observations were made too close to the wavelength region where
  the lines change from emission to absorption and therefore disappear.

Title: Diffractional image degradation due to radial, parabolic
    temperature distributions in a lens.
Authors: Greve, A.; Hunt, G. C.
Bibcode: 1974Optik..40..332G
Altcode:
  No abstract at ADS

Title: The Strehl number of degraded diffraction patterns.
Authors: Greve, A.; Hunt, G. C.
Bibcode: 1974Optik..40...18G
Altcode:
  No abstract at ADS

Title: A remark on turbulence and `production' limited telescopes
Authors: Greve, A.
Bibcode: 1973SoPh...29..263G
Altcode:
  The image degradation due to residual surface inaccuracies of the main
  optical element of a telescope is compared with the image degradation
  due to atmospheric turbulence.

Title: High resolution ultraviolet solar spectra in the region 2765
    2822 Å
Authors: Greve, A.; McKeith, C. D.; McKeith, N. E.
Bibcode: 1973SoPh...28..289G
Altcode:
  Wavelengths and identifications of the near ultraviolet solar spectrum
  are presented. The data were obtained during the rocket flight of an
  interferometer spectrograph with a spectral resolution of 0.03 Å.

Title: High-resolution ultraviolet solar spectra in the region 2765 -
    2822 Å.
Authors: Greve, A.; McKeith, C. D.; McKeith, N. E.
Bibcode: 1973MNRAS.161..289G
Altcode:
  No abstract at ADS

Title: Das solare UV-Spektrum in der Umgebung der Mg II-Resonanzlinien
Authors: Greve, A.; McKeith, C. D.; McKeith, N. E.
Bibcode: 1973MitAG..34..107G
Altcode:
  No abstract at ADS

Title: 25 Jahre Beobachtungen der solaren UV Strahlung.
Authors: Greve, A.
Bibcode: 1973Stern..49..212G
Altcode:
  No abstract at ADS

Title: Een teleskoop voor het infrarood.
Authors: Greve, A.
Bibcode: 1973HemD...71...62G
Altcode:
  No abstract at ADS

Title: 25 jaar UV-waarnemingen van de zon.
Authors: Greve, A.
Bibcode: 1973HemD...71..170G
Altcode:
  No abstract at ADS

Title: On the Size Distribution of Turbulent Elements in the Earth's
    Atmosphere
Authors: Greve, A.
Bibcode: 1972SoPh...24..243G
Altcode:
  Solar scintillation measurements made by Wessely and Mitchell are used
  to derive the size distribution of turbulent elements in the Earth's
  atmosphere. Assuming a stationary state of the Earth's atmosphere,
  the production rate of the turbulent elements is calculated.

Title: Nieuwe grote optische telescopen.
Authors: Greve, A.
Bibcode: 1972HemD...70..219G
Altcode:
  No abstract at ADS

Title: On the center to limb variation of the separation of the Mg
    ii, H<SUB>2</SUB> and K<SUB>2</SUB> emission peaks
Authors: Greve, A.
Bibcode: 1971SoPh...16..328G
Altcode:
  From observations of the center to limb variation of the emission
  peaks of the MgII, H and K lines the optical thickness of the emitting
  layer for a simplified geometrical model has been calculated to
  be ≈ 300. The source function was approximated by a second order
  polynomial. The turbulent velocities of the emitting layer are found
  to be ≈ 6.8 km/sec, in agreement with other observations.

Title: De 1.52 meter-spiegeltelescop van de Universiteits-Sterrenwacht
    van Wenen.
Authors: Greve, A.
Bibcode: 1971HemD...69..320G
Altcode:
  No abstract at ADS

Title: High quantum number emission and absorption lines of Fe V
    viii, Fe  xv, O  iii, O  vii of the sun
Authors: Greve, A.
Bibcode: 1970SoPh...15..380G
Altcode:
  No abstract at ADS

Title: Ca II en Mg II, H- en K-lijnen van de zon.
Authors: Greve, A.
Bibcode: 1970HemD...68..157G
Altcode:
  No abstract at ADS

