Author name code: madsen
ADS astronomy entries on 2022-09-14
author:"Madsen, Chad Allen" 
------------------------------------------------------------------------  

Title: The Airborne Infrared Spectrometer: Development,
    Characterization, and the 2017 August 21 Eclipse Observation
Authors: Samra, Jenna E.; Marquez, Vanessa; Cheimets, Peter; DeLuca,
   Edward E.; Golub, Leon; Hannigan, James W.; Madsen, Chad A.; Vira,
   Alisha; Adams, Arn
Bibcode: 2022AJ....164...39S
Altcode: 2021arXiv210509419S
  On 2017 August 21, the Airborne Infrared Spectrometer (AIR-Spec)
  observed the total solar eclipse at an altitude of 14 km from aboard the
  NSF/NCAR Gulfstream V research aircraft. The instrument successfully
  observed the five coronal emission lines that it was designed to
  measure: Si X 1.431 μm, S XI 1.921 μm, Fe IX 2.853 μm, Mg VIII
  3.028 μm, and Si IX 3.935 μm. Characterizing these magnetically
  sensitive emission lines is an important first step in designing
  future instruments to monitor the coronal magnetic field, which
  drives space weather events, as well as coronal heating, structure,
  and dynamics. The AIR-Spec instrument includes an image stabilization
  system, feed telescope, grating spectrometer, and slit-jaw imager. This
  paper details the instrument design, optical alignment method, image
  processing, and data calibration approach. The eclipse observations
  are described and the available data are summarized.

Title: New Observations of the IR Emission Corona from the 2019 July
    2 Eclipse Flight of the Airborne Infrared Spectrometer
Authors: Samra, Jenna E.; Madsen, Chad A.; Cheimets, Peter; DeLuca,
   Edward E.; Golub, Leon; Marquez, Vanessa; Reyes, Naylynn Tañón
Bibcode: 2022ApJ...933...82S
Altcode: 2021arXiv210608760S
  The Airborne Infrared Spectrometer (AIR-Spec) was commissioned during
  the 2017 total solar eclipse, when it observed five infrared coronal
  emission lines from a Gulfstream V research jet owned by the National
  Science Foundation and operated by the National Center for Atmospheric
  Research. The second AIR-Spec research flight took place during the
  2019 July 2 total solar eclipse across the south Pacific. The 2019
  eclipse flight resulted in seven minutes of observations, during
  which the instrument measured all four of its target emission lines:
  S XI 1.393 μm, Si X 1.431 μm, S XI 1.921 μm, and Fe IX 2.853
  μm. The 1.393 μm S XI line was detected for the first time, and
  probable first detections were made of Si XI 1.934 μm and Fe X 1.947
  μm. The 2017 AIR-Spec detection of Fe IX was confirmed and the first
  observations were made of the Fe IX line intensity as a function of
  solar radius. Telluric absorption features were used to calibrate the
  wavelength mapping, instrumental broadening, and throughput of the
  instrument. AIR-Spec underwent significant upgrades in preparation for
  the 2019 eclipse observation. The thermal background was reduced by a
  factor of 30, providing a 5.5× improvement in signal-to-noise ratio,
  and the postprocessed pointing stability was improved by a factor of 5
  to &lt;10″ rms. In addition, two imaging artifacts were identified
  and resolved, improving the spectral resolution and making the 2019
  data easier to interpret.

Title: Exploring the middle corona: new instrumentation to address
    science questions critical to understanding the thermal structure
    and dynamic evolution of the middle corona
Authors: DeLuca, Edward; Winebarger, Amy; Reeves, Katharine; Golub,
   Leon; Samra, Jenna; Madsen, Chad; Rivera, Yeimy; Karna, Nishu;
   Savage, Sabrina; Seaton, Daniel; West, Matthew; Downs, Cooper; Del
   Zanna, Giulio
Bibcode: 2021AGUFMSH25F2150D
Altcode:
  The global structure of the largely unexplored middle corona determines
  the physical properties of the inner heliosphere, affects the formation
  and acceleration of the solar wind, and controls the dynamics of
  eruptive events. Tracing the short and long term global evolution
  of the extended corona, identifying changes in corona/heliosphere
  connectivity and following the dynamic evolution of eruptive events
  in this unexplored region will provide observational data that will
  clarify how the corona transitions from closed to open, illuminate the
  genesis of coronal mass ejections, and provide input for the design
  of the next generation of physics based space weather forecasts. This
  poster outlines several critical science questions and identifies the
  measurements that are required to make substantial progress towards
  addressing the questions. We review and discuss the instrumentation
  necessary to capture the observations needed for meaningful progress
  in this area as well as the role of simulations in the interpretation
  of the observations.

Title: Probing the Lower Solar Chromosphere Via Dynamical Signatures
    of UV Bursts in Cold Lines
Authors: Chaparro, Victoria; Madsen, Chad; DeLuca, Edward
Bibcode: 2021AGUFMSH45B2368C
Altcode:
  UV Bursts are small scale brightenings identified by dramatic
  intensification and broadening of emission lines often accompanied
  by absorption features from cold metallic ions. They can be used
  as probes of plasma conditions in the lower solar atmosphere since
  their spectral features suggest they are magnetic reconnection
  events in the cool lower chromosphere. We present a spatial and
  temporal analysis of the intensification and broadening of the Si IV
  1393.78 Å and Cl I 1351.66 Å lines observed by the Interface Region
  Imaging Spectrograph (IRIS) to trace magnetic reconnection outflows
  through the lower chromosphere. We employ a semi-automated UV burst
  detection algorithm by applying single-Gaussian fits (SGF) to the Si
  IV 1394 Å line in IRIS sit-and-stare data. We first isolate the likely
  candidate population in the SGF parameter space, reducing the candidate
  field from hundreds of thousands to only a few thousand spectra. We
  then manually search these candidate spectra for Ni II 1393.33 Å
  absorption. Following detection, we focus on the Cl I 1391.66 Å
  line to observe the influence of UV bursts over lower chromospheric
  dynamics. This is done by constructing a series of space-time plots of
  the peak intensity, Doppler velocity, and line width SGF parameters
  of Cl I 1391.66 Å to measure time lags between its intensification
  and broadening, allowing us to estimate downflow velocities in the
  lower chromosphere under UV burst conditions. This is possible because
  the peak intensity of Cl I 1391.66 Å is dependent on fluorescence
  from C II 1335.71 Å, a line strongly emitted by the UV burst source,
  while its width only broadens when the emitting material is impacted
  by a material flow. This study establishes the power of UV bursts as
  probes of dynamical phenomena in the lower chromosphere, a region that
  is notoriously difficult to observe directly. Furthermore, it lays the
  groundwork for future exploration of the often overlooked cool emission
  lines in the IRIS spectral passbands and their potential as physical
  diagnostics. This work is part of the NSF-REU Solar Physics program at
  SAO, grant number AGS-1850750. Keywords: Solar Magnetic Reconnection,
  Active Solar Chromosphere, Solar Ultraviolet Emission.

Title: An Airborne Coronal Emission Surveyor (ACES) for Total Solar
    Eclipse Observations
Authors: Samra, Jenna; Cheimets, Peter; DeLuca, Edward; Madsen, Chad;
   Marquez, Vanessa
Bibcode: 2021AGUFMED13B..01S
Altcode:
  The Airborne Coronal Emission Surveyor (ACES) is a new imaging Fourier
  transform spectrometer (FTS) that will explore the large-scale
  coronal infrared (IR) emission spectrum during the April 8, 2024
  total solar eclipse. ACES will fly along the path of totality on the
  NSF/NCAR Gulfstream V High-performance Instrumented Airborne Platform
  for Environmental Research (GV HIAPER), with a stabilized solar feed
  provided by the Airborne Stabilized Platform for InfraRed Experiments
  (ASPIRE). During the 6-minute total eclipse, ACES will map emission
  line intensity in the 14 micron wavelength region at over a 0.73 0.5
  field of view (FOV). A GV altitude of at least 13 km will enable it to
  survey the near and mid-IR with minimal atmospheric interference. ACES
  is the latest in a line of NSF-funded airborne instruments developed by
  Smithsonian Astrophysical Observatory to explore the IR emission corona
  from GV HIAPER. Previous instruments include the Airborne InfraRed
  Spectrometer (AIR-Spec), a cryogenic grating spectrometer that observed
  the 2017 and 2019 eclipses, and ASPIRE, which improves on the AIR-Spec
  image stabilization system to provide a 20 cm solar feed stabilized to
  5 arcsec RMS over 1 second. Unlike AIR-Spec, which observed a narrow
  range of wavelengths and imaged along only one dimension, ACES will
  survey the entire 14 micron (2,50010,000 cm-1) spectral range at high
  (0.2 cm-1) spectral resolution and in two spatial dimensions. ACES is
  expected to observe neutral helium as well as 18 forbidden lines of
  ionized magnesium, silicon, sulfur, argon, calcium, and iron, and it
  may measure weaker lines of those and other ions. The mission addresses
  science questions related to the strength of different emission lines in
  different regions of the corona, the relative radiative to collisional
  excitation in each line, the best temperature and density diagnostics
  in the passband, and the variation of elemental abundances across the
  corona. The instrument consists of a condenser telescope, cryogenic
  Michaelson interferometer, achromatic lens, and IR camera. The 2024
  eclipse flight will serve as the ACES commissioning flight.

Title: Calibration of the Marshall Grazing Incidence X-Ray
    Spectrometer Experiment. II. Flight Instrument Calibration
Authors: Athiray, P. S.; Winebarger, Amy R.; Champey, Patrick;
   Kobayashi, Ken; Savage, Sabrina; Beabout, Brent; Beabout, Dyana;
   Broadway, David; Bruccoleri, Alexander R.; Cheimets, Peter;
   Golub, Leon; Gullikson, Eric; Haight, Harlan; Heilmann, Ralf K.;
   Hertz, Edward; Hogue, William; Johnson, Steven; Kegley, Jeffrey;
   Kolodziejczak, Jeffery; Madsen, Chad; Schattenburg, Mark L.; Siler,
   Richard; Vigil, Genevieve D.; Wright, Ernest
Bibcode: 2021ApJ...922...65A
Altcode:
  The Marshall Grazing Incidence X-ray Spectrometer (MaGIXS) is a
  sounding rocket experiment that observes the soft X-ray spectrum of
  the Sun from 6.0-24 Å (0.5-2.0 keV), successfully launched on 2021
  July 30. End-to-end alignment of the flight instrument and calibration
  experiments are carried out using the X-ray and Cryogenic Facility
  at NASA Marshall Space Flight Center. In this paper, we present the
  calibration experiments of MaGIXS, which include wavelength calibration,
  measurement of line spread function, and determination of effective
  area. Finally, we use the measured instrument response function to
  predict the expected count rates for MaGIXS flight observation looking
  at a typical solar active region.

Title: Calibration of the MaGIXS experiment II: Flight Instrument
    Calibration
Authors: Athiray, P. S.; Winebarger, Amy R.; Champey, Patrick;
   Kobayashi, Ken; Savage, Sabrina; Beabout, Brent; Beabout, Dyana;
   Broadway, David; Bruccoleri, Alexander R.; Cheimets, Peter;
   Golub, Leon; Gullikson, Eric; Haight, Harlan; Heilmann, Ralf K.;
   Hertz, Edward; Hogue, William; Johnson, Steven; Kegley, Jeffrey;
   Kolodziejczak, Jeffery; Madsen, Chad; Schattenburg, Mark L.; Siler,
   Richard; Vigil, Genevieve D.; Wright, Ernest
Bibcode: 2021arXiv210901720A
Altcode:
  The Marshall Grazing Incidence X-ray Spectrometer (MaGIXS) is a
  sounding rocket experiment that observes the soft X-ray spectrum of
  the Sun from 6.0 - 24 Angstrom (0.5 - 2.0 keV), successfully launched
  on 30 July 2021. End-to-end alignment of the flight instrument
  and calibration experiments are carried out using the X-ray and
  Cryogenic Facility (XRCF) at NASA Marshall Space Flight Center. In
  this paper, we present the calibration experiments of MaGIXS, which
  include wavelength calibration, measurement of line spread function,
  and determination of effective area. Finally, we use the measured
  instrument response function to predict the expected count rates for
  MaGIXS flight observation looking at a typical solar active region

Title: Characterization of UV Bursts Using Line-Ratio Density
    Diagnostics
Authors: Conneely, F.; Madsen, C. A.; DeLuca, E.
Bibcode: 2020AGUFMSH0010005C
Altcode:
  We compare abundance-sensitive and abundance-insensitive electron
  density diagnostics for a large sample of UV burst spectra. These bursts
  are compact (~1 arcsec), short-lived (~minutes to hours) active-region
  phenomena, forming in the cool lower solar atmosphere and capable of
  reaching nearly 100,000K. They exhibit significant intensification and
  broadening/splitting of the Si IV 1393.76/1402.77 Å lines, which we
  believe are signatures of magnetic reconnection. Bursts also display
  absorption from cool metallic ions Ni II and Fe II, suggesting that they
  form deep in the chromosphere. These unusual phenomena are critical to
  understanding energy and mass transfer within the solar atmosphere,
  possibly contributing to upper-chromospheric and coronal heating and
  affecting the energetics and dynamics of the lower atmosphere. We
  employ a semi-automated detection algorithm to assemble a sample of
  over 9,800 UV burst spectra for Interface Region Imaging Spectrograph
  (IRIS) observations of two active regions spanning several days. <P
  />We perform line-ratio density diagnostics using O IV and S IV pairs as
  well as a Si IV / O IV ratio. Since bursts are characterized by strong
  Si IV 1402.77 Å emission and O IV 1401.16 Å also appears strongly in a
  majority of burst spectra, the Si IV / O IV diagnostic has the potential
  to be a robust density indicator. There is a significant uncertainty
  around the use of different-species diagnostics due to their strong
  dependence on relative atomic abundances, which are poorly constrained
  in the chromosphere. We compare the Si IV / O IV diagnostic with the
  abundance-insensitive ratios of O IV 1399.78 Å / O IV 1401.16 Å, O IV
  1401.16 Å / O IV 1404.81 Å, and S IV 1404.85 Å / S IV 1406.06 Å and
  comment on the viability of the Si IV /O IV method in burst regions. We
  also find the rates of detection for these lines in our spectra. Our
  density analysis provides useful constraints on UV burst formation
  altitudes and aids in the comparison of observations to models. <P
  />This work is supported by the NSF-REU Solar Physics program at SAO,
  grant number AGS-1850750 and NASA H-SR grant number 80NSSC18K1124.

Title: EUV imaging and spectroscopy for improved space weather
    forecasting
Authors: Golub, Leon; Cheimets, Peter; DeLuca, Edward E.; Madsen, Chad
   A.; Reeves, Katharine K.; Samra, Jenna; Savage, Sabrina; Winebarger,
   Amy; Bruccoleri, Alexander R.
Bibcode: 2020JSWSC..10...37G
Altcode:
  Accurate predictions of harmful space weather effects are mandatory
  for the protection of astronauts and other assets in space, whether in
  Earth or lunar orbit, in transit between solar system objects, or on the
  surface of other planetary bodies. Because the corona is multithermal
  (i.e., structured not only in space but also in temperature),
  wavelength-separated data provide crucial information that is not
  available to imaging methods that integrate over temperature. The
  extreme ultraviolet (EUV) wavelengths enable us to focus directly on
  high temperature coronal plasma associated with solar flares, coronal
  mass ejections (CMEs), and shocked material without being overwhelmed by
  intensity from the solar disk. Both wide-field imaging and spectroscopic
  observations of the solar corona taken from a variety of orbits (e.g.,
  Earth, L1, or L5) using suitably-chosen EUV instrumentation offer
  the possibility of addressing two major goals to enhance our space
  weather prediction capability, namely: (1) Improve our understanding
  of the coronal conditions that control the opening and closing of the
  corona to the heliosphere and consequent solar wind streams, and (2)
  Improve our understanding of the physical processes that control the
  early evolution of CMEs and the formation of shocks, from the solar
  surface out into the extended corona.

Title: Eclipse Results from the Airborne Infrared Spectrometer
    (AIR-Spec) and the Extreme-ultraviolet Imaging Spectrometer (EIS)
Authors: Tañón Reyes, N.; Samra, J.; Madsen, C.; DeLuca, E.
Bibcode: 2020AAS...23521009T
Altcode:
  The Sun's dynamic outermost atmospheric layer, the corona, exhibits
  extremely high temperatures meaning it's in a state of hydrostatic
  and thermodynamic disequilibrium which leads to solar activity,
  such as flares and coronal mass ejections. This activity can
  dramatically affect humanity's infrastructure and technology in
  space and on Earth. Understanding the coronal magnetic field would
  allow for predictions of these magnetic reconnection-driven violent
  events. Measuring the magnetic field is possible via the study of
  magnetically sensitive emission lines in the infrared (IR) via the
  Zeeman effect. The corona emits some IR emission lines, however, the
  solar surface's intensity overwhelms them. To study these lines, we can
  observe total solar eclipses wherein the moon blocks out the surface's
  continuous emission. The Airborne Infrared Spectrometer (AIR-Spec) is
  a pathfinder for future infrared spectrometers and spectro-polarimeters
  that will measure the coronal magnetic field. On July 2, 2019 AIR-Spec
  observed the total solar eclipse over the South Pacific from onboard
  an aircraft. It flew at 13km to avoid low-altitude water vapor, the
  primary absorber of IR radiation on Earth. AIR-Spec characterized four
  emission lines to determine their viability for future instruments to
  measure the coronal magnetic field. Comparing the intensity gradients
  for the observed IR lines with extreme-ultraviolet (EUV) lines from
  the EUV Imaging Spectrometer (EIS) gives us information regarding
  the excitation processes in the corona, providing improvements to the
  atomic models. We also determine the value of the IR lines as plasma
  temperature and density diagnostics, using EIS data to supplement
  our analysis. The analysis of the temperature and density will help
  explain the behavior of the plasma, which will allow the mapping of the
  coronal magnetic field. Lastly, we discuss how AIR-Spec will continue
  its mission during both the 2020 and 2024 total solar eclipses as
  well as its influence on future spectro-polarimetric missions. This
  work is supported by the NSF-REU solar physics program at SAO [grant#
  AGS-1560313] and the NSF Airborne InfraRed Spectrograph (AIR-Spec)
  2019 Eclipse Flight [award# 1822314].

Title: Total Solar Eclipse Science and Outreach in Perú
Authors: Tañón Reyes, N.; Madsen, C.
Bibcode: 2020AAS...23523907T
Altcode:
  On July 2nd, 2019, the Airborne Infrared Spectrometer (AIR-Spec)
  observed the total solar eclipse over the South Pacific from onboard
  an aircraft as a pathfinder for future infrared spectrometers and
  spectro-polarimeters that will measure the Sun's coronal magnetic
  field. In addition to research, we led outreach activities in Spanish,
  including lectures and tours, regarding the scientific importance of
  studying solar eclipses for predicting solar activity. The lecture was
  a 45-minute talk in Spanish at the Universidad Nacional de Ingeniería
  (trans. National University of Engineering) in Lima, Perú. The
  next day, following the lecture, we spoke with the local media,
  embassy officials and local scientists in Spanish about our project and
  instrument. This meeting with journalists led to a front-page story in a
  local newspaper regarding our scientific study, allowing the science to
  reach a broad audience across the capital. Through these interactions,
  we learned colloquia and other research-oriented outreach events in
  Spanish are rare. Therefore, this information is largely inaccessible to
  those who are not fluent in English, stressing the need for this type of
  work in Spanish-speaking communities. While preparing for these events,
  we learned that fellow native Spanish speakers at our home institution
  have not given a colloquium in Spanish and were not comfortable with
  the idea as they do not have the vocabulary. The scientific papers
  and textbooks we read, even those originating from Spanish-speaking
  countries, are predominantly in English, and therefore the technical
  terms are not easily learned or found. As a result, we recognized if
  one does not know English, one loses the opportunity to learn about
  the current status of scientific research. Having this information
  readily available in Spanish will also allow for more people to get
  involved in scientific endeavors and for a better exchange of knowledge
  between communities. For that reason, during the eclipse in South
  America next year, we plan on hosting more events such as these. This
  work is supported by the NSF-REU solar physics program at SAO [grant#
  AGS-1560313] and the NSF Airborne InfraRed Spectrograph (AIR-Spec)
  2019 Eclipse Flight [award# 1822314].

Title: The 2019 AIR-Spec Mission: Results from Coordinated Infrared
    and EUV Spectroscopic Observations of the Corona During the South
    Pacific Total Solar Eclipse
Authors: Madsen, C. A.; Samra, J.; Tañón Reyes, N.; DeLuca, E.
Bibcode: 2019AGUFMSH33A..04M
Altcode:
  After a successful maiden voyage in 2017, The Airborne Infrared
  Spectrometer (AIR-Spec) embarked on another observing mission, this
  time targeting the July 2, 2019 total solar eclipse over the South
  Pacific Ocean. AIR-Spec, designed specifically for operation onboard
  aircraft, observes coronal infrared emission lines between 1.4 μm and
  3.0 μm during total solar eclipses. It proved its viability during
  the August 21, 2017 total solar eclipse and underwent significant
  design improvements in preparation for the 2019 mission, resulting
  in a vastly reduced thermal background and more precise pointing
  control. These improvements allowed for an unprecedented view of the
  underexplored near-infrared corona, a wavelength regime critical to the
  advancement of solar physics due to the potential for direct coronal
  magnetic field measurements via spectrally resolved observations of the
  Zeeman effect. In pursuit of this goal, and with coordinated support
  from the Extreme-ultraviolet Imaging Spectrometer (EIS), we present
  the results from a number of studies involving four infrared lines
  detected by AIR-Spec: S XI 1.39 μm, Si X 1.43 μm, S XI 1.92 μm, and
  Fe IX 2.85 μm. First, we explore the effects of photoexcitation upon
  the Si X 1.43 μm line by comparing its spatial radiance profile to
  Si X lines in the EUV, further constraining atomic models of coronal
  emission such as CHIANTI. Next, we probe the diagnostic potential
  of the electron density-sensitive S XI 1.39/1.92 μm line pair while
  characterizing the uncertainties arising from atmospheric absorption in
  and around the S XI 1.39 μm line. Also, as an extension to previously
  published research, we take advantage of the improved sensitivity and
  stability of AIR-Spec to perform more precise temperature diagnostics
  using the emission measure (EM) loci method. Finally, we demonstrate
  how these results will influence future AIR-Spec missions and upcoming
  spectro-polarimetric instruments, including those planned for the Daniel
  K. Inouye Solar Telescope (DKIST) as well as a proposed balloon-based
  coronagraph for coronal magnetic field measurements.

Title: High-Altitude Instrumentation for Infrared Observations of
    the Solar Corona
Authors: Samra, J.; Cheimets, P.; DeLuca, E.; Golub, L.; Hannigan,
   J. W.; Judge, P. G.; Madsen, C. A.; Marquez, V.; Tañón Reyes, N.;
   Tomczyk, S.
Bibcode: 2019AGUFMSH43B..07S
Altcode:
  High-altitude infrared remote sensing is a promising new method for
  measuring coronal plasma and magnetic fields. We present new results
  from a recent airborne eclipse mission and outline concepts for future
  airborne and balloon-based instruments for coronal spectroscopy
  and spectro-polarimetry. <P />The airborne infrared spectrometer
  (AIR-Spec) was commissioned during the 2017 total solar eclipse,
  when it observed five infrared coronal emission lines from the NSF
  Gulfstream V research jet. These magnetically sensitive emission lines
  of highly ionized magnesium, silicon, sulfur, and iron are promising
  candidates for future observations of the coronal magnetic field, and
  their characterization is an important first step toward developing
  the next generation of instrumentation for coronal magnetometry. The
  second AIR-Spec research flight took place during the July 2, 2019
  total solar eclipse across the south Pacific. Higher sensitivity and
  reduced jitter enabled more precise measurements of emission line
  properties and plasma density, temperature, and line-of-sight velocity
  up to one solar radius from the solar limb. Atmospheric absorption
  was significant, even at altitude, and atmospheric modeling was
  required to extract accurate line intensities. <P />AIR-Spec is a slit
  spectrometer that measures light over a 1.55 solar radius field of view
  in three spectral passbands between 1.4 and 3 microns. The successful
  eclipse missions overcame a number of engineering challenges, centered
  around maintaining adequate resolution and signal-to-noise ratio in
  a compact and inexpensive package on a moving platform. AIR-Spec is a
  pathfinder for future infrared spectrometers and spectro-polarimeters,
  including a balloon-based coronagraph that will measure the global
  coronal magnetic field and an airborne spectrometer that will survey
  the infrared emission corona during a future eclipse.

Title: Solar Eclipse Observations from the Ground and Air from 0.31
    to 5.5 Microns
Authors: Judge, Philip; Berkey, Ben; Boll, Alyssa; Bryans, Paul;
   Burkepile, Joan; Cheimets, Peter; DeLuca, Edward; de Toma, Giuliana;
   Gibson, Keon; Golub, Leon; Hannigan, James; Madsen, Chad; Marquez,
   Vanessa; Richards, Austin; Samra, Jenna; Sewell, Scott; Tomczyk,
   Steven; Vera, Alysha
Bibcode: 2019SoPh..294..166J
Altcode:
  We present spectra and broad-band polarized light data from a novel
  suite of instruments deployed during the 21st August 2017 total solar
  eclipse. Our goals were to survey solar spectra at thermal infrared
  wavelengths during eclipse, and to test new technology for measuring
  polarized coronal light. An infrared coronal imaging spectrometer,
  flown at 14.3 km altitude above Kentucky, was supported on the ground
  by observations from Madras, Oregon (elevation 683 m) and Camp Wyoba
  on Casper Mountain, Wyoming (2402 m). In Wyoming we deployed a new
  infrared Fourier Transform Spectrometer (FTS), three low-dispersion
  spectrometers loaned to us by Avantes, a novel visible-light camera
  PolarCam, sensitive to linear polarization, and one of two infrared
  cameras from FLIR Systems, the other operated at Madras. Circumstances
  of eclipse demanded that the observations spanned 17:19 to 18:26
  UT. We analyze spectra of the limb photosphere, the chromosphere,
  prominences, and coronal lines from 310 nm to 5.5 μm. We calibrated
  data photometrically using the solar disk as a source. Between different
  spectrometers, the calibrations were consistent to better than 13%. But
  the sensitivities achieved were insufficient to detect coronal lines
  from the ground. The PolarCam data are in remarkable agreement with
  polarization data from the K-Cor synoptic instrument on Mauna Loa, and
  with FLIR intensity data acquired in Madras. We discuss new results,
  including a detection of the He I 1083 nm multiplet in emission during
  the whole of totality. The combination of the FTS and AIR-Spec spectra
  reveals for the first time the effects of the telluric extinction
  on the infrared coronal emission lines, to be observed with upcoming
  Daniel K. Inouye Solar Telescope.

Title: Unfolding Overlapped Slitless Imaging Spectrometer Data for
    Extended Sources
Authors: Winebarger, Amy R.; Weber, Mark; Bethge, Christian; Downs,
   Cooper; Golub, Leon; DeLuca, Edward; Savage, Sabrina; del Zanna,
   Giulio; Samra, Jenna; Madsen, Chad; Ashraf, Afra; Carter, Courtney
Bibcode: 2019ApJ...882...12W
Altcode: 2018arXiv181108329W
  Slitless spectrometers can provide simultaneous imaging and spectral
  data over an extended field of view, thereby allowing rapid data
  acquisition for extended sources. In some instances, when the object
  is greatly extended or the spectral dispersion is too small, there
  may be locations in the focal plane where emission lines at different
  wavelengths contribute. It is then desirable to unfold the overlapped
  regions in order to isolate the contributions from the individual
  wavelengths. In this paper, we describe a method for such an unfolding,
  using an inversion technique developed for an extreme ultraviolet
  imaging spectrometer and coronagraph named the COronal Spectroscopic
  Imager in the EUV (COSIE). The COSIE spectrometer wavelength range
  (18.6-20.5 nm) contains a number of strong coronal emission lines and
  several density sensitive lines. We focus on optimizing the unfolding
  process to retrieve emission measure maps at constant temperature,
  maps of spectrally pure intensity in the Fe XII and Fe XIII lines,
  and density maps based on both Fe XII and Fe XIII diagnostics.

Title: Coronal Plasma Characterization via Coordinated Infrared and
    Extreme Ultraviolet Observations of a Total Solar Eclipse
Authors: Madsen, Chad A.; Samra, Jenna E.; Del Zanna, Giulio; DeLuca,
   Edward E.
Bibcode: 2019ApJ...880..102M
Altcode: 2019arXiv190110425M
  We present coordinated coronal observations of the 2017 August 21 total
  solar eclipse with the Extreme-ultraviolet Imaging Spectrometer (EIS)
  and the Airborne Infrared Spectrometer (AIR-Spec). These instruments
  provide an unprecedented view of the solar corona in two disparate
  wavelength regimes, the extreme ultraviolet (EUV) and the near- to
  mid-infrared (IR), opening new pathways for characterizing the complex
  coronal plasma environment. During totality, AIR-Spec sampled coronal
  IR spectra near the equatorial west limb, detecting strong sources
  of Mg VIII, S XI, Si IX, and Si X in two passbands encompassing 1.4-4
  μm. We apply an intensity-ratio diagnostic to a strong resonant Fe XII
  line pair arising from the coordinated EIS observations. This results
  in a high-resolution map of electron density throughout the shared
  EIS/AIR-Spec field of view. Electron density measurements allow us to
  produce a similar map of plasma temperature using emission measure
  (EM) loci analysis as applied to 27 EIS emission lines, providing
  temperatures of 10<SUP>6.12</SUP> ± 10<SUP>3.5</SUP> K along the
  limb and 10<SUP>6.19</SUP> ± 10<SUP>3.5</SUP> K at about 100″
  outward. Applying EM loci analysis to AIR-Spec IR spectra coadded
  over two 31″ wide ranges centered at two locations, 30″ and
  100″ from the limb, produces temperatures consistent with the EIS
  data, albeit suffering from moderate uncertainties. Regardless, we
  demonstrate that EUV spectral data are valuable constraints to coronal
  IR emission models, and will be powerful supplements for future IR
  solar observatories, particularly DKIST.

Title: Solar Ultraviolet Bursts
Authors: Young, Peter R.; Tian, Hui; Peter, Hardi; Rutten, Robert J.;
   Nelson, Chris J.; Huang, Zhenghua; Schmieder, Brigitte; Vissers, Gregal
   J. M.; Toriumi, Shin; Rouppe van der Voort, Luc H. M.; Madjarska, Maria
   S.; Danilovic, Sanja; Berlicki, Arkadiusz; Chitta, L. P.; Cheung, Mark
   C. M.; Madsen, Chad; Reardon, Kevin P.; Katsukawa, Yukio; Heinzel, Petr
Bibcode: 2018SSRv..214..120Y
Altcode: 2018arXiv180505850Y
  The term "ultraviolet (UV) burst" is introduced to describe small,
  intense, transient brightenings in ultraviolet images of solar active
  regions. We inventorize their properties and provide a definition
  based on image sequences in transition-region lines. Coronal signatures
  are rare, and most bursts are associated with small-scale, canceling
  opposite-polarity fields in the photosphere that occur in emerging flux
  regions, moving magnetic features in sunspot moats, and sunspot light
  bridges. We also compare UV bursts with similar transition-region
  phenomena found previously in solar ultraviolet spectrometry and
  with similar phenomena at optical wavelengths, in particular Ellerman
  bombs. Akin to the latter, UV bursts are probably small-scale magnetic
  reconnection events occurring in the low atmosphere, at photospheric
  and/or chromospheric heights. Their intense emission in lines with
  optically thin formation gives unique diagnostic opportunities
  for studying the physics of magnetic reconnection in the low solar
  atmosphere. This paper is a review report from an International Space
  Science Institute team that met in 2016-2017.

Title: Instrument Calibration of the Interface Region Imaging
    Spectrograph (IRIS) Mission
Authors: Wülser, J. -P.; Jaeggli, S.; De Pontieu, B.; Tarbell,
   T.; Boerner, P.; Freeland, S.; Liu, W.; Timmons, R.; Brannon, S.;
   Kankelborg, C.; Madsen, C.; McKillop, S.; Prchlik, J.; Saar, S.;
   Schanche, N.; Testa, P.; Bryans, P.; Wiesmann, M.
Bibcode: 2018SoPh..293..149W
Altcode:
  The Interface Region Imaging Spectrograph (IRIS) is a NASA small
  explorer mission that provides high-resolution spectra and images of
  the Sun in the 133 - 141 nm and 278 - 283 nm wavelength bands. The
  IRIS data are archived in calibrated form and made available to the
  public within seven days of observing. The calibrations applied to
  the data include dark correction, scattered light and background
  correction, flat fielding, geometric distortion correction, and
  wavelength calibration. In addition, the IRIS team has calibrated the
  IRIS absolute throughput as a function of wavelength and has been
  tracking throughput changes over the course of the mission. As a
  resource for the IRIS data user, this article describes the details
  of these calibrations as they have evolved over the first few years
  of the mission. References to online documentation provide access to
  additional information and future updates.

Title: Results of the IRIS UV Burst Survey, Part I: Active Regions
    Tracked Limb to Limb
Authors: Madsen, C. A.; DeLuca, E.
Bibcode: 2017AGUFMSH43A2802M
Altcode:
  We present results from the first phase of an effort to thoroughly
  characterize UV bursts within the Interface Region Imaging Spectrograph
  (IRIS) data catalogue. The observational signatures of these phenomena
  include dramatically intensified and broadened NUV/FUV emission line
  profiles with absorption features from cool metallic ions. These
  properties suggest that UV bursts originate from plasma at transition
  region temperatures (≥ 80,000 K) which is deeply embedded in the
  cool lower chromosphere ( 5,000 K). Rigorously characterizing the
  energetic and dynamical properties of UV bursts is crucial since they
  have considerable potential to heat active region chromospheres and
  could provide critical constraints for models of magnetic reconnection
  in these regions. The survey first focuses on IRIS observations of
  active regions tracked from limb to limb. All observations consist
  of large field-of-view raster scans of 320 or 400 steps each, which
  allow for widespread detection of many burst profiles at the expense
  of having limited short-term time evolution information. We detect
  bursts efficiently by applying a semi-automated single-Gaussian
  fitting technique to Si IV 1393.8 Å emission profiles that isolates
  the distinct burst population in a 4-D parameter space. The robust
  sample of NUV/FUV burst spectra allows for precise constraints of
  properties critical for modeling reconnection in the chromosphere,
  including outflow kinetic energy, density estimates from intensity
  ratios of Si IV 1402.8 Å and O IV 1401.2 Å emission lines, and
  coincident measures of emission in other wavelengths. We also track
  burst properties throughout the lifetimes of their host active regions,
  noting changes in detection rate and preferential location as the
  active regions evolve. Finally, the tracked active region observations
  provide a unique opportunity to investigate line-of-sight effects on
  observed UV burst spectral properties, particularly the strength of Ni
  II 1393.3 Å absorption, a feature that may be important in identifying
  the upward conduction of burst thermal energy through the chromosphere.

Title: Exploring the Time Evolution of Cool Metallic Absorption
    Features in UV Burst Spectra
Authors: Belmes, K.; Madsen, C. A.; DeLuca, E.
Bibcode: 2017AGUFMSH51C2499B
Altcode:
  UV bursts are compact brightenings in active regions that appear in
  UV images. They are identified through three spectroscopic features:
  (1) broadening and intensification of NUV/FUV emission lines, (2)
  the presence of optically thin Si IV emission, and (3) the presence
  of absorption features from cool metallic ions. Properties (2) and (3)
  imply that bursts exist at transition region temperatures (≥ 80,000
  K) but are located in the cooler lower chromosphere ( 5,000 K). Their
  energetic and dynamical properties remain poorly constrained. Improving
  our understanding of this phenomena could help us further constrain the
  energetic and dynamical properties of the chromosphere, as well as give
  us insight into whether or not UV bursts contribute to chromospheric
  and/or coronal heating. We analyzed the time evolution of UV bursts
  using spectral data from the Interface Region Imaging Spectrograph
  (IRIS). We inspected Si IV 1393.8 Å line profiles for Ni II 1393.3
  Å absorption features to look for signs of heating. Weakening of
  absorption features over time could indicate heating of the cool ions
  above the burst, implying that thermal energy from the burst could
  rapidly conduct upward through the chromosphere. To detect the spectral
  profiles corresponding to bursts, we applied a four-parameter Gaussian
  fit to every profile in each observation and took cuts in parameter
  space to isolate the bursts. We then manually reviewed the remaining
  profiles by looking for a statistically significant appearance of
  Ni II 1393.3 Å absorption. We quantified these absorption features
  by normalizing the Si IV 1393.8 Å emission profiles and measuring
  the maximum fractional extinction in each. Our preliminary results
  indicate that Ni II 1393.3 Å absorption may undergo a cycle of
  strengthening and weakening throughout a burst's lifetime. However,
  further investigation is needed for confirmation. This work is supported
  by the NSF-REU solar physics program at SAO, grant number AGS-1560313.

Title: ASPIRE - Airborne Spectro-Polarization InfraRed Experiment
Authors: DeLuca, E.; Cheimets, P.; Golub, L.; Madsen, C. A.; Marquez,
   V.; Bryans, P.; Judge, P. G.; Lussier, L.; McIntosh, S. W.; Tomczyk, S.
Bibcode: 2017AGUFMSH13B2480D
Altcode:
  Direct measurements of coronal magnetic fields are critical for
  taking the next step in active region and solar wind modeling and
  for building the next generation of physics-based space-weather
  models. We are proposing a new airborne instrument to make these key
  observations. Building on the successful Airborne InfraRed Spectrograph
  (AIR-Spec) experiment for the 2017 eclipse, we will design and build a
  spectro-polarimeter to measure coronal magnetic field during the 2019
  South Pacific eclipse. The new instrument will use the AIR-Spec optical
  bench and the proven pointing, tracking, and stabilization optics. A new
  cryogenic spectro-polarimeter will be built focusing on the strongest
  emission lines observed during the eclipse. The AIR-Spec IR camera,
  slit jaw camera and data acquisition system will all be reused. The
  poster will outline the optical design and the science goals for ASPIRE.

Title: Eclipse Science Results from the Airborne Infrared Spectrometer
    (AIR-Spec)
Authors: Samra, J.; Cheimets, P.; DeLuca, E.; Golub, L.; Judge, P. G.;
   Lussier, L.; Madsen, C. A.; Marquez, V.; Tomczyk, S.; Vira, A.
Bibcode: 2017AGUFMSH24A..06S
Altcode:
  We present the first science results from the commissioning flight
  of the Airborne Infrared Spectrometer (AIR-Spec), an innovative
  solar spectrometer that will observe the 2017 solar eclipse from
  the NSF/NCAR High-Performance Instrumented Airborne Platform for
  Environmental Research (HIAPER). During the eclipse, AIR-Spec will
  image five magnetically sensitive coronal emission lines between 1.4
  and 4 microns to determine whether they may be useful probes of coronal
  magnetism. The instrument will measure emission line intensity, FWHM,
  and Doppler shift from an altitude of over 14 km, above local weather
  and most of the absorbing water vapor. Instrumentation includes an image
  stabilization system, feed telescope, grating spectrometer, infrared
  camera, and visible slit-jaw imager. Results from the 2017 eclipse
  are presented in the context of the mission's science goals. AIR-Spec
  will identify line strengths as a function of position in the solar
  corona and search for the high frequency waves that are candidates
  for heating and acceleration of the solar wind. The instrument will
  also identify large scale flows in the corona, particularly in polar
  coronal holes. Three of the five lines are expected to be strong in
  coronal hole plasmas because they are excited in part by scattered
  photospheric light. Line profile analysis will probe the origins
  of the fast and slow solar wind. Finally, the AIR-Spec measurements
  will complement ground based eclipse observations to provide detailed
  plasma diagnostics throughout the corona. AIR-Spec will measure infrared
  emission of ions observed in the visible from the ground, giving insight
  into plasma heating and acceleration at radial distances inaccessible
  to existing or planned spectrometers.

Title: Waves, Bursts, and Instabilities: A Multi-Scale Investigation
    of Energetic Plasma Processes in the Solar Chromosphere and Transition
    Region
Authors: Madsen, Chad Allen
Bibcode: 2017PhDT.......264M
Altcode:
  The chromosphere and transition region of the solar atmosphere provide
  an interface between the cool photosphere ( 6000 K) and the hot corona
  ( 1 million K). Both layers exhibit dramatic deviations from thermal
  and hydrostatic equilibrium in the form of intense plasma heating
  and mass transfer. The exact mechanisms responsible for transporting
  energy to the upper atmosphere remain unknown, but these must include
  a variety of energetic processes operating across many spatial and
  temporal scales. This dissertation comprises three studies of possible
  mechanisms for plasma heating and energy transport in the solar
  chromosphere and transition region. The first study establishes the
  theoretical framework for a collisional, two-stream plasma instability
  in the quiet-Sun chromosphere similar to the Farley-Buneman instability
  which actively heats the E-region of Earth's ionosphere. After deriving
  a linear dispersion relationship and employing a semi-empirical model of
  the chromosphere along with carefully computed collision frequencies,
  this analysis shows that the threshold electron drift velocity for
  triggering the instability is remarkably low near the temperature
  minimum where convective overshoots could continuously trigger the
  instability. The second study investigates simultaneous Interface Region
  Imaging Spectrograph (IRIS) observations of magnetohydrodynamic (MHD)
  waves in the chromospheres and transition regions of sunspots. By
  measuring the dominant wave periods, apparent phase velocities,
  and spatial and temporal separations between appearances of two
  observationally distinct oscillatory phenomena, the data show that these
  are consistent with upward-propagating slow magnetoacoustic modes tied
  to inclined magnetic field lines in the sunspot, providing a conduit
  for photospheric seismic energy to transfer upward. The third and
  final study focuses on intense, small-scale ( 1 arcsec) active region
  brightenings known as IRIS UV bursts. These exhibit dramatic FUV/NUV
  emission line splitting and deep absorption features, suggesting that
  they result from reconnection events embedded deep in the cool lower
  chromosphere. IRIS FUV spectral observations and Solar Dynamics Obser-
  vatory/Helioseismic and Magnetic Imager (SDO/HMI) magnetograms of a
  single evolving active region reveal that bursts prefer to form during
  the active region's emerging phase. These bursts tend to be spatially
  coincident with small-scale, photospheric, bipolar regions of upward
  and downward magnetic flux that dissipate as the active region matures.

Title: Initial Results of a Large-scale Statistical Survey of
    Small-scale UV Bursts with IRIS and SDO
Authors: Madsen, C. A.; DeLuca, E.
Bibcode: 2016AGUFMSH31B2570M
Altcode:
  UV bursts are small-scale ( 1 arcsec or less) brightenings observed
  in the NUV/FUV passbands of the Interface Region Imaging Spectrograph
  (IRIS). These peculiar phenomena are found exclusively in active regions
  and exhibit dramatic and defining spectroscopic characteristics. In
  particular, they present intense broadening and splitting, often
  in excess of 70 km s-1, in all bright emission lines observable by
  IRIS. Furthermore, these broadened lines also display strong absorption
  from cool metallic ions such as Fe II and Ni II which typically
  populate the chromosphere. These features suggest that bursts are
  bidirectional plasma flows at transition region temperatures embedded
  much farther down in the cool chromosphere. To better characterize
  these phenomena, we have launched a statistical survey encompassing
  the entire IRIS data catalogue to date and its accompanying data from
  the Atmospheric Imaging Assembly (AIA) and Helioseismic and Magnetic
  Imager (HMI). We sample a wide variety of IRIS observations of Si IV
  lines, ranging from large 400-step rasters for large detection rates
  to short-cadence sit-and-stare observations to provide in-depth time
  evolution data of individual bursts. Detection is streamlined by a
  semi-automated method that isolates characteristic burst spectra based
  on single-Gaussian fit parameters, greatly reducing search times in the
  vast IRIS catalogue. Our initial results demonstrate that UV bursts
  tend to appear when active regions are young and actively emerging,
  preferring to populate poorly developed inversion lines composed
  of numerous small mixed-polarity regions. Burst occurrence rates
  peak at 30-70 per hour in young active regions, decreasing as those
  regions age. We also find dramatic variations in spectral morphology
  in spatial scans of bursts with many split into distinct, opposing,
  resolved regions of blueshifts and redshifts. Finally, we find little
  evidence for coronal counterparts in AIA 171 Å, but we do find that
  a significant ratio of bursts coincide with localized bright features
  in AIA 1700 Å, lending support to the link between bursts and Ellerman
  bombs. With further involvement in the survey, we hope to constrain the
  burst/Ellerman bomb coincidence, the time evolution of burst spectral
  morphologies, and the distribution of their peak kinetic energies.

Title: Tracking Sunspot Waves Across the Solar Disk using IRIS
Authors: Sager, H. A.; Madsen, C. A.; DeLuca, E.
Bibcode: 2016AGUFMSH21E2568S
Altcode:
  Waves can be observed in the transition region and upper chromosphere of
  sunspots. Two particular phenomena, running waves and umbral flashes,
  can be seen in the 1400 Å and 2796 Å bandpasses, respectively,
  on slit-jaw images from the Interface Region Imaging Spectrograph
  (IRIS). How running waves propagate through the solar atmosphere is
  still a topic of debate revolving around two theories. The trans-sunspot
  theory explains that these waves propagate radially across the sunspot
  from its center just as they appear visually. The upward propagating
  theory illustrates that these waves are tied to the magnetic field
  lines and are therefore slow magnetoacoustic waves, indicating that the
  observed apparent motion of the waves is not real. Previous studies
  focused on individual observations at a fixed viewing angle, leaving
  the results susceptible to line-of-sight bias. To test for this bias, we
  observed the leading sunspots of AR 11836 and AR 12546 as they traveled
  from the disk center to the western limb. To assess the two theories,
  we applied global wavelet analysis to our high-pass filtered slit-jaw
  images and were able to find the spatial distribution of dominate wave
  periods for both phenomena. We then compared the period distribution
  to magnetic field line inclinations from the Helioseismic and Magnetic
  Imager (HMI). From this, we find a clear correlation between magnetic
  field line inclination and wave period as both increase outward from the
  sunspot center. The period increases from 180 s from the sunspot center
  to 240 s near the edge of the penumbra for all of our viewing angles,
  nullifying the existence of a line-of-sight bias and lending credence
  to the upward propagating theory. The importance of discovering how
  these waves are moving through the solar atmosphere could provide a
  mechanism for transporting local seismic energy from the photosphere
  to the corona.

Title: Are IRIS Bombs Connected to Ellerman Bombs?
Authors: Tian, Hui; Xu, Zhi; He, Jiansen; Madsen, Chad
Bibcode: 2016ApJ...824...96T
Altcode: 2016arXiv160405423T
  Recent observations by the Interface Region Imaging Spectrograph
  (IRIS) have revealed pockets of hot gas (∼2-8 × 10<SUP>4</SUP> K)
  potentially resulting from magnetic reconnection in the partially
  ionized lower solar atmosphere (IRIS bombs; IBs). Using joint
  observations between IRIS and the Chinese New Vacuum Solar Telescope,
  we have identified 10 IBs. We find that 3 are unambiguously and 3
  others are possibly connected to Ellerman bombs (EBs), which show
  intense brightening of the extended {{{H}}}<SUB>α </SUB> wings without
  leaving an obvious signature in the {{{H}}}<SUB>α </SUB> core. These
  bombs generally reveal the following distinct properties: (1) the O
  IV 1401.156 Å and 1399.774 Å lines are absent or very weak; (2) the
  Mn I 2795.640 Å line manifests as an absorption feature superimposed
  on the greatly enhanced Mg II k line wing; (3) the Mg II k and h lines
  show intense brightening in the wings and no dramatic enhancement in the
  cores; (4) chromospheric absorption lines such as Ni II 1393.330 Å and
  1335.203 Å are very strong; and (5) the 1700 Å images obtained with
  the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory
  reveal intense and compact brightenings. These properties support the
  formation of these bombs in the photosphere, demonstrating that EBs
  can be heated much more efficiently than previously thought. We also
  demonstrate that the Mg II k and h lines can be used to investigate EBs
  similarly to {{{H}}}<SUB>α </SUB>, which opens a promising new window
  for EB studies. The remaining four IBs obviously have no connection
  to EBs and they do not have the properties mentioned above, suggesting
  a higher formation layer, possibly in the chromosphere.

Title: Observations of Small-scale IRIS Bombs (Reconnection Events)
    in an Evolving Active Region
Authors: Madsen, C. A.; Tian, H.; DeLuca, E. E.
Bibcode: 2015AGUFMSH31B2414M
Altcode:
  We present the first Interface Region Imaging Spectrograph (IRIS)
  observations of small-scale bombs evolving with their host active
  region. Bombs appear most clearly in the IRIS 1330 Å and 1400 Å
  slit-jaw images as small (~1 arcsec), compact, intense brightenings at
  transition region temperatures. Their NUV/FUV emission spectra exhibit
  dramatic line splitting and strong absorption features indicative of
  bidirectional flows from magnetic reconnection embedded deep within the
  cool lower solar atmosphere. The bombs may contribute significantly
  to the heating of the solar atmosphere in active regions; however,
  it's unclear how prevalent the bombs are throughout the lifetime of an
  active region. Using a semi-automated detection method, we locate bombs
  within AR 11850 over the course of four observations from 06:00 UT on
  September 25, 2013 until 11:30 UT the next day. The active region is
  first observed in an emerging phase and rapidly grows into a mature
  active region with well-developed sunspots. The bomb occurrence rate
  drops dramatically as the active region fully emerges. We also find
  that the bombs fall into two distinct populations: one appears largely
  during active region emergence and contains a majority of the bombs,
  while the other population is present regardless of active region
  age. The first population of bombs is typically found embedded in the
  low-lying loops prominent in the young active region. Furthermore,
  we use Solar Dynamics Observatory/Helioseismic and Magnetic Imager
  (SDO/HMI) line-of-sight magnetograms to show that the bombs associated
  with the first population occur at the boundaries between the upward
  and downward flux of small, isolated bipolar regions. These regions
  dissipate as the active region emerges and reconfigures its magnetic
  field into two large network patches of upward and downward flux with a
  clear inversion line. The second, smaller population of bombs usually
  occurs far from the active region loop structures in the plage and
  sunspot penumbrae. They are associated with the boundaries between
  strong upward or downward flux and regions where the magnetic field
  is perpendicular to the line of sight.

Title: Observations of Umbral Flashes and Running Sunspot Waves with
    the Interface Region Imaging Spectrograph
Authors: Madsen, Chad A.; Tian, Hui; DeLuca, Edward E.
Bibcode: 2015ApJ...800..129M
Altcode:
  We present simultaneous, high-resolution, multi-temperature observations
  of running waves and umbral flashes in a sunspot with the Interface
  Region Imaging Spectrograph. We analyze intensity variations in
  slit-jaw images to investigate the relationship between running
  waves in the 1400 Å (Si IV/transition region) passband and umbral
  flashes in the 2796 Å (Mg II/chromosphere) passband. Using global
  wavelet analysis, we find that the dominant wave periods increase
  from approximately 150 s near the sunspot center to about 300 s in
  the penumbra in both passbands. This coincides extremely well with
  the radially increasing inclination of magnetic field lines observed
  with Solar Dynamics Observatory/Helioseismic and Magnetic Imager,
  suggesting that the waves are propagating vertically along the inclined
  field lines. Furthermore, apparent horizontal velocities for running
  waves decrease from about 12 km s<SUP>-1</SUP> in the umbra to about
  4 km s<SUP>-1</SUP> in the penumbra which is predicted by the same
  inclined field geometry. Finally, we find that umbral flashes lead
  running waves in both the spatial and temporal domains. The former
  result is attributable to the inclined field geometry; however, the
  geometry does not predict the radially increasing time lag which is
  likely due to the opacity difference between the emission lines that
  dominate the two passbands. These results suggest that running waves
  and umbral flashes both originate from photospheric p-mode oscillations
  and are manifestations of upward-propagating slow magnetoacoustic modes
  at different altitudes and temperatures. The apparent trans-sunspot
  propagation of running waves is not real but rather an image of these
  upward-propagating modes traveling along field lines of radially
  increasing inclination.

Title: Jorge Melnick Retires from ESO
Authors: Madsen, C.
Bibcode: 2014Msngr.158...59M
Altcode:
  No abstract at ADS

Title: First Simulations of a Collisional Two-Stream Instability in
    the Chromosphere
Authors: Oppenheim, Meers; Dimant, Yakov; Madsen, Chad Allen;
   Fontenla, Juan
Bibcode: 2014AAS...22430205O
Altcode:
  Observations and modeling shows that immediately above the temperature
  minimum in the solar atmosphere, a steep rise from below 4,000 K to
  over 6,000K occurs. Recent papers show that a collisional two-stream
  plasma instability called the Farley-Buneman Instability can develop
  at the altitudes where this increase occurs. This instability may
  play an important role in transferring energy from turbulent neutral
  flows originating in the photosphere to the mid-chromosphere in the
  form of heat. Plasma turbulence resulting from this instability could
  account for some or most of this intense chromospheric heating. This
  paper presents a set of simulations showing the development and
  evolution of the Farley-Buneman Instability (FBI) applicable to the
  chromosphere. It compares these results with the better-understood
  ionospheric FBI. It examines the linear behavior and the dependence
  of growth rates for a range of altitudes and driving flows. It also
  presents the first study of FBI driven plasma nonlinearities and
  turbulence in the chromosphere. This research should help us evaluate
  the FBI as a mechanism to convert neutral flow and turbulence energy
  into electron thermal energy in the quiet Sun.

Title: Theory of Collisional Two-Stream Plasma Instabilities in the
    Solar Chromosphere
Authors: Madsen, Chad Allen; Dimant, Yakov; Oppenheim, Meers;
   Fontenla, Juan
Bibcode: 2014AAS...22432303M
Altcode:
  The solar chromosphere experiences intense heating just above its
  temperature minimum. The heating increases the electron temperature
  in this region by over 2000 K. Furthermore, it exhibits little time
  variation and appears widespread across the solar disk. Although
  semi-empirical models, UV continuum observations, and line emission
  measurements confirm the existence of the heating, its source remains
  unexplained. Potential heating sources such as acoustic shocks,
  resistive dissipation, and magnetic reconnection via nanoflares
  fail to account for the intensity, persistence, and ubiquity of the
  heating. Fontenla (2005) suggested turbulence from a collisional
  two-stream plasma instability known as the Farley-Buneman instability
  (FBI) could contribute significantly to the heating. This instability
  is known to heat the plasma of the E-region ionosphere which bears many
  similarities to the chromospheric plasma. However, the ionospheric
  theory of the FBI does not account for the diverse ion species found
  in the solar chromosphere. This work develops a new collisional,
  two-stream instability theory appropriate for the chromospheric plasma
  environment using a linear fluid analysis to derive a new dispersion
  relationship and critical E x B drift velocity required to trigger the
  instability. Using a 1D, non-local thermodynamic equilibrium, radiative
  transfer model and careful estimates of collision rates and magnetic
  field strengths, we calculate the trigger velocities necessary to induce
  the instability throughout the chromosphere. Trigger velocities as low
  as 4 km s^-1 are found near the temperature minimum, well below the
  local neutral acoustic speed in that region. From this, we expect the
  instability to occur frequently, converting kinetic energy contained
  in neutral convective flows from the photosphere into thermal energy
  via turbulence. This could contribute significantly to chromospheric
  heating and explain its persistent and ubiquitous nature.

Title: The Multi-species Farley-Buneman Instability in the Solar
    Chromosphere
Authors: Madsen, Chad A.; Dimant, Yakov S.; Oppenheim, Meers M.;
   Fontenla, Juan M.
Bibcode: 2014ApJ...783..128M
Altcode: 2013arXiv1308.0305M
  Empirical models of the solar chromosphere show intense electron
  heating immediately above its temperature minimum. Mechanisms such as
  resistive dissipation and shock waves appear insufficient to account for
  the persistence and uniformity of this heating as inferred from both
  UV lines and continuum measurements. This paper further develops the
  theory of the Farley-Buneman instability (FBI) which could contribute
  substantially to this heating. It expands upon the single-ion theory
  presented by Fontenla by developing a multiple-ion-species approach
  that better models the diverse, metal-dominated ion plasma of the solar
  chromosphere. This analysis generates a linear dispersion relationship
  that predicts the critical electron drift velocity needed to trigger
  the instability. Using careful estimates of collision frequencies and
  a one-dimensional, semi-empirical model of the chromosphere, this new
  theory predicts that the instability may be triggered by velocities as
  low as 4 km s<SUP>-1</SUP>, well below the neutral acoustic speed. In
  the Earth's ionosphere, the FBI occurs frequently in situations where
  the instability trigger speed significantly exceeds the neutral acoustic
  speed. From this, we expect neutral flows rising from the photosphere
  to have enough energy to easily create electric fields and electron
  Hall drifts with sufficient amplitude to make the FBI common in the
  chromosphere. If so, this process will provide a mechanism to convert
  neutral flow and turbulence energy into electron thermal energy in
  the quiet Sun.

Title: Retirement of Massimo Tarenghi
Authors: Madsen, C.
Bibcode: 2013Msngr.153...39M
Altcode:
  Massimo Tarenghi, chronologically MPG/ESO project scientist, NTT project
  manager, VLT programme manager and first Director, ALMA Director and
  ESO Representative in Chile, has retired after 35 years at ESO. A
  brief summary of his achievements is presented.

Title: Presenting the ESO Story: One Hundred and Fifty Messengers
Authors: Madsen, C.
Bibcode: 2012Msngr.150...74M
Altcode:
  Since 1974, The ESO Messenger has been one of ESO's primary
  communication channels to the outside world in particular. It has
  provided a window not only onto the organisation, its projects and
  people, but also onto the research carried out by ESO's ever-growing
  user community. Last but not least, today it constitutes a fascinating
  historical source, documenting the life and evolution of ESO over the
  last 38 years.

Title: Large-Scale Intrinsic Alignments of Galaxies
Authors: Brainerd, Tereasa G.; Agustsson, I.; Madsen, C. A.; Edmonds,
   J. A.
Bibcode: 2010AAS...21540906B
Altcode: 2010BAAS...42..234B
  We compute the two-point image correlation function for bright
  galaxies in the seventh data release of the Sloan Digital Sky Survey
  (SDSS) over angular scales 0.01 arcmin to 120 arcmin and projected
  separations 0.01 Mpc to 10 Mpc. We restrict our analysis to SDSS
  galaxies with spectroscopic redshifts and we find strong evidence for
  intrinsic alignment of the galaxy images. On scales greater than 40
  kpc, the intrinsic alignment of the SDSS galaxy images compares well
  with the intrinsic alignment of galaxy images in a LCDM universe,
  provided we impose Gaussian-random errors on the position angles of
  the theoretical galaxies with a dispersion of 25 degrees. Without
  the inclusion of these errors, the amplitude of the two-point image
  correlation function for the theoretical galaxies is a factor of
  2 higher than it is for the SDSS galaxies. We interpret this as a
  combination of modest position angle errors for the SDSS galaxies,
  as well as a need for modest misalignment of mass and light in the
  theoretical galaxies. The intrinsic alignment of the SDSS galaxies shows
  no dependence on the specific star formation rates of the galaxies and,
  at most, a very weak dependence on the colors and stellar masses of
  the galaxies. At the 3 sigma level, however, we find an indication
  that the images of the most luminous SDSS galaxies are more strongly
  aligned with each other than are the images of the least luminous SDSS
  galaxies. This work was supported by NSF grant AST-0708468.

Title: Large-Scale Intrinsic Alignment of Galaxy Images
Authors: Brainerd, Tereasa G.; Agustsson, Ingolfur; Madsen, Chad A.;
   Edmonds, Jeffrey A.
Bibcode: 2009arXiv0904.3095B
Altcode:
  We compute the two-point image correlation function for bright galaxies
  in the seventh data release of the Sloan Digital Sky Survey (SDSS) over
  angular scales 0.01' &lt;= \theta &lt;= 120' and projected separations
  0.01 Mpc &lt;= r &lt;= 10 Mpc. We restrict our analysis to SDSS galaxies
  with accurate spectroscopic redshifts, and we find strong evidence for
  intrinsic alignment of the galaxy images. On scales greater than r ~
  40 kpc, the intrinsic alignment of the SDSS galaxy images compares well
  with the intrinsic alignment of galaxy images in a Lambda-CDM universe,
  provided we impose Gaussian-random errors on the position angles of
  the theoretical galaxies with a dispersion of 25 degrees. Without
  the inclusion of these errors, the amplitude of the two-point image
  correlation function for the theoretical galaxies is a factor of
  ~2 higher than it is for the SDSS galaxies. We interpret this as a
  combination of modest position angle errors for the SDSS galaxies,
  as well as a need for modest misalignment of mass and light in the
  theoretical galaxies. The intrinsic alignment of the SDSS galaxies shows
  no dependence on the specific star formation rates of the galaxies and,
  at most, a very weak dependence on the colors and stellar masses of the
  galaxies. At the ~3-sigma level, however, we find an indication that
  the images of the most luminous SDSS galaxies are more strongly aligned
  with each other than are the images of the least luminous SDSS galaxies.

Title: ASTRONET: Public Outreach
Authors: Ros, R. M.; Fosbury, R.; Christensen, L. L.; Del Toro Iniesta,
   J. C.; Fucili, L.; Hill, R.; Lorenzen, D.; Madsen, C.; Newsam, A.;
   Pickwick, A.; Radeva, V.
Bibcode: 2009CAPJ....5...26R
Altcode:
  We have all seen the spectacular images that the Hubble Space Telescope
  and other such observatories have revealed to the world. Their haunting
  splendour inspires and compels us as artists. But how can we capture
  the elusive essence of space in our own work?

Title: ESO Education and Public Outreach for IYA2009
Authors: Pierce-Price, D.; Madsen, C.; Boffin, H. J.; Argandoña, G.
Bibcode: 2008ca07.conf..274P
Altcode:
  ESO, the European Organisation for Astronomical Research in the Southern
  Hemisphere, is planning a range of education and public outreach
  activities for the International Year of Astronomy 2009 (IYA2009). In
  addition to support for IYA2009 global Cornerstone Projects, these
  will include local, national, and international activities, aimed at
  the general public, the interested public, and school students.

Title: ESO at the AAS, the AAAS and in Dublin
Authors: Boffin, H.; Madsen, C.
Bibcode: 2007Msngr.127...69B
Altcode:
  The great variety of new distribution meth-ods and tools available
  does not replace face-to-face communication, which re-mains a most
  valuable activity in presenting ESO and its future needs. Face-to-face
  communication, in turn, takes many forms ranging from formal lectures
  and speeches, through less formal and infor-mal meetings and briefings,
  e.g. with de-cision makers or media representatives, to information
  stands at fairs and confer-ences. Information stands often provide a
  physical basis for important personal encounters. In 2006, ESO's Public
  Affairs Department organised or participated in more than 20 events,
  involving exhibitions, briefings and VIP visits. This con-stitutes a
  marked increase over the pre-vious years, on the one hand reflecting
  the growing importance and visibility of ESO, and, on the other hand,
  a necessity, given the need to enlist wide support for ESO's ambitious
  future projects.

Title: Open House at the ESO Headquarters
Authors: Madsen, C.
Bibcode: 2006Msngr.126...50M
Altcode: 2006Msngr.126f..50M
  On 15 October, the ESO Headquarters opened its doors to the public
  as part of the All-Campus Open House organised in connection with the
  inauguration of the extension of the underground line U6 from Munich to
  the Garching campus. The day was blessed with clear skies and plenty
  of sunshine, and a large number of citizens took advantage of the
  opportunity to visit the campus. The estimated number of visitors at
  ESO was close to 3000 people, a record number. Another record was set
  by the number of ESO staff who, in anticipation of the high num-ber
  of guests, volunteered to spend their Sunday at work to explain what
  ESO is doing and why it is important.

Title: Universe Awareness For Young Children
Authors: Scorza, C.; Miley, G.; Ödman, C.; Madsen, C.
Bibcode: 2006IAUSS...2E..39S
Altcode:
  Universe Awareness (UNAWE) is an international programme that will
  expose economically disadvantaged young children aged between 4 and 10
  years to the inspirational aspects of modern astronomy. The programme
  is motivated by the premise that access to simple knowledge about the
  Universe is a basic birth right of everybody. These formative ages
  are crucial in the development of a human value system. This is also
  the age range in which children can learn to develop a 'feeling' for
  the vastness of the Universe. Exposing young children to such material
  is likely to broaden their minds and stimulate their world-view. The
  goals of Universe Awareness are in accordance with two of the United
  Nations Millennium goals, endorsed by all 191 UN member states,
  namely (i) the achievement of universal primary education and (ii)
  the promotion of gender equality in schools. We propose to commence
  Universe Awareness with a pilot project that will target disadvantaged
  regions in about 4 European countries (possibly Spain, France, Germany
  and The Netherlands) and several non-EU countries (possibly Chile,
  Colombia, India, Tunisia, South Africa and Venezuela). There will
  be two distinct elements in the development of the UNAWE program:
  (i) Creation and production of suitable UNAWE material and delivery
  techniques, (ii) Training of educators who will coordinate UNAWE in each
  of the target countries. In addition to the programme, an international
  network of astronomy outreach will be organised. We present the first
  results of a pilot project developed in Venezuela, where 670 children
  from different social environments, their teachers and members of an
  indigenous tribe called Ye´kuana from the Amazon region took part
  in a wonderful astronomical and cultural exchange that is now being
  promoted by the Venezuelan ministry of Education at the national level.

Title: ESO's Astronomy Education Programme
Authors: Pierce-Price, D. P. I.; Boffin, H.; Madsen, C.
Bibcode: 2006IAUSS...2E..23P
Altcode:
  ESO, the European Organisation for Astronomical Research in the
  Southern Hemisphere, has operated a programme of astronomy education
  for some years, with a dedicated Educational Office established in
  2001. We organise a range of activities, which we will highlight
  and discuss in this presentation. Many are run in collaboration with
  the European Association for Astronomy Education (EAAE), such as the
  "Catch a Star!" competition for schools, now in its fourth year. A
  new endeavour is the ALMA Interdisciplinary Teaching Project (ITP). In
  conjunction with the EAAE, we are creating a set of interdisciplinary
  teaching materials based around the Atacama Large Millimeter Array
  project. The unprecedented astronomical observations planned with ALMA,
  as well as the uniqueness of its site high in the Atacama Desert,
  offer excellent opportunities for interdisciplinary teaching that
  also encompass physics, engineering, earth sciences, life sciences,
  and culture. Another ongoing project in which ESO takes part is the
  "Science on Stage" European science education festival, organised by
  the EIROforum - the group of seven major European Intergovernmental
  Research Organisations, of which ESO is a member. This is part of the
  European Science Teaching Initiative, along with Science in School,
  a newly-launched European journal for science educators. Overviews of
  these projects will be given, including results and lessons learnt. We
  will also discuss possibilities for a future European Astronomy Day
  project, as a new initiative for European-wide public education.

Title: Walloon Space Days
Authors: Madsen, C.
Bibcode: 2006Msngr.124...42M
Altcode:
  On 28-29 March, the Cluster Wallonie Espace, mainly a partnership
  of companies in the Walloon ‘Space Valley', or-ganised the first
  so-called ‘W Space Days' at the Colonster Castle, located on the
  premises of the University of Liège. The primary aim of these days
  is to encourage meetings between professionals in the sector and to
  identify new scientific and technological opportunities. They should
  also help to raise awareness of the activities of the space sector
  amongst the general public and young people in particular. Indeed the
  event successfully brought together scientists, industrialists, funding
  agencies and policymakers. On the first day, some 210 representatives
  of research centres, industries and organisations from 13 countries
  in Europe participated in the professional event, while the next
  day was a ‘public day'. The first morning's programme comprised a
  series of talks, including ELT presentations by Roberto Gilmozzi and
  Philippe Dierickx.

Title: Finnish Parliamentary Committee at ESO Headquarters
Authors: Madsen, C.
Bibcode: 2006Msngr.124...38M
Altcode:
  Finnish Parliamentary Committee at ESO Headquarters

Title: ESO at AAAS
Authors: Madsen, C.
Bibcode: 2006Msngr.123...61M
Altcode:
  No abstract at ADS

Title: Universe Awareness . An inspirational programme for
    economically disadvantaged young children.
Authors: Ödman, C. J.; Scorza, C.; Miley, G. K.; Madsen, C.
Bibcode: 2006MmSAI..77.1014O
Altcode:
  The beauty of the sky and its connection with the human development have
  inspired generations with wonder. Astronomy conveys the excitement
  of science to the public. Considerable resources are devoted to
  outreach in developed countries, with spectacular images produced
  by modern astronomical facilities and astronomical discoveries that
  change our views of the Universe. <P />Universe Awareness (UNAWE) is a
  programme for children between 4 and 10 years old. The formative ages
  of 4 to 10 years are crucial in child development. Children of that
  age can appreciate the beauty of astronomical objects and develop a
  ``feeling'' for the vastness of the Universe. Exposing young children
  to such material is likely to broaden their minds and stimulate their
  world-view. The programme concentrates on economically disadvantaged
  young children because most other children will be exposed to some
  knowledge about the Universe and disparities between advantaged
  and disadvantaged children increase with age. Venezuela hosted a
  successful pilot project in 2006. From spontaneous observation of the
  sky to a teacher-training workshop in the "Centro de Investigaciones
  de Astronomía" in Mérida, this was a wonderful experience for
  participants and organisers alike. This shows how successful the UNAWE
  programme can be.

Title: ESO at Cer 2005
Authors: Madsen, C.
Bibcode: 2005Msngr.122...48M
Altcode:
  On November 14-15, the Brussels Exhibition Centre (Heysel) was the home
  of a major international conference on science communication with the
  title “Communicating European Research” (CER 2005).

Title: Science on Stage 2005
Authors: Pierce-Price, D.; Boffin, H.; Madsen, C.
Bibcode: 2005Msngr.122...47P
Altcode:
  “Science on Stage”, the European Science Teaching Festival, is
  a major educational outreach programme for science teachers. It aims
  to identify and foster innovation within formal science education by
  means of exchange of best practice, workshops and seminars involving
  educators from all over Europe.

Title: Universe Awareness for Young Children
Authors: Miley, G.; Madsen, C.; Scorza de Appl, C.
Bibcode: 2005Msngr.121...66M
Altcode:
  Universe Awareness (UNA) is an international programme that will expose
  economically-disadvantaged young children, between ages 4 and 10 years,
  in developed and developing countries to the inspirational aspects of
  modern astronomy.

Title: Towards a Europe of Knowledge and Innovation?
Authors: Madsen, C.
Bibcode: 2005Msngr.120...46M
Altcode:
  THE EUROPEAN SOCIETIES ARE undergoing fast changes these years. The
  need to manage the European integration process as well as to develop
  adequate solutions in the face of globalization and the pressure on
  the ‘European way of life' led the Heads of states and governments
  of the EU to set for themselves the goal of developing the most dynamic
  knowledge-based economy in the world within a 10-year period. Both the
  goals and the policies to reach them are known as the Lisbon Agenda and
  the Lisbon Process, respectively, reminding us that it was in the city
  of Lisbon - in the year 2000 - that this development was started. Now,
  at half-time, the process has been reviewed and the governments have
  acknowledged the need to focus on the most essential policy areas that
  must be developed to achieve success.

Title: Richard West retires
Authors: Madsen, C.
Bibcode: 2005Msngr.120...56M
Altcode:
  It is hard to believe, but after 35 years of service, Richard West has
  retired from ESO. Born 1941 in Copenhagen, Richard did his baccalaureate
  in 1959. In 1964, he obtained his degree (Mag. scient. et cand. mag.) in
  astronomy and astrophysics at Copenhagen University, followed by a
  period as Assistant Professor (Amanuensis) at Copenhagen University
  Observatory. In 1970, he joined ESO as Assistant Astronomer to the
  ESO Director General, Adriaan Blaauw.

Title: ESO Presentation in Copenhagen
Authors: Madsen, C.; D'Odorico, S.
Bibcode: 2004Msngr.118...71M
Altcode:
  On November 8, ESO continued its series of presentations in
  memberstates with an event in Copenhagen. So far events have been
  organised in Belgium, Finland, Portugal, Sweden, Switzerland and
  the United Kingdom. The purpose of these presentations is to raise
  the awareness of ESO amongst decision-makers, academia and the
  media. Over time, the scope and specific focus of the national events
  have varied, considering the particular circumstances and the wishes
  of the national hosts, and accordingly, the presentation in Denmark
  was primarily oriented towards industry. The meeting was initiated
  by the Royal Danish Consulate General in Munich in conjunction with
  the Confederation of Danish Industries and the Ministry for Science,
  Technology and Innovation. Leading up to the meeting, several articles
  about ESO had appeared in the Danish press and the 2nd TV Channel
  featured a report on the ESO projects also in connection with the event.

Title: Report on the EuroScience Open Forum 2004
Authors: Madsen, C.
Bibcode: 2004Msngr.117...66M
Altcode:
  SCIENCE reigned supreme in Stockholm for a period of four days in
  late August this year, as some 1800 scientists, administrators,
  policy-makers and media representatives from 68 countries convened
  at the EUROSCIENCE Open Forum, the first pan- European inter- and
  transdisciplinary science meeting on our Continent.

Title: Serving European Science: The EIROforum Collaboration
Authors: Madsen, C.
Bibcode: 2004Msngr.116...42M
Altcode:
  OVER THE LAST FEW years, the idea of a “European Research Area”
  (ERA) has gained strong support among science policy makers and,
  increasingly, among scientists themselves. The goal of the ERA is
  to establish a single “market” for research on our continent,
  allowing for better co-ordination of research efforts, synergies
  between projects, the achievement of “critical mass” (both human
  and financial) and thus to strengthen the competitiveness of European
  research. These goals necessitate deep structural changes in the way
  science is organised, breaking up existing borderlines and barriers
  between national research systems in Europe.

Title: Visit EIROFORUM at ESOF 2004
Authors: Madsen, C.
Bibcode: 2004Msngr.116...48M
Altcode:
  The EuroScience Open Forum (ESOF2004) is the first pan-European
  interdisciplinary scientific conference, modelled on the well-known
  and highly successful meetings in the US by the American Association
  for the Advancement of Science (AAAS). ESOF2004 will be held at the
  Stockholm City Conference Centre in Stockholm, Sweden, this summer,
  between 25-28 August. It is intended to continue with ESOF meetings
  on a biannual basis in the future.

Title: Astronomy and Space Science in the European Print Media
Authors: Madsen, C.
Bibcode: 2003ASSL..290...67M
Altcode: 2003asco.book...67M
  No abstract at ADS

Title: Astronomy Communication
Authors: Heck, A.; Madsen, C.
Bibcode: 2003ASSL..290.....H
Altcode: 2003asco.book.....H
  Astronomers communicate all the time, with colleagues of course, but
  also with managers and administrators, with decision makers and takers,
  with social representatives, with the news media, and with the society
  at large. Education is naturally part of the process. Astronomy
  communication must take into account several specificities: the
  astronomy community is rather compact and well organized world-wide;
  astronomy has penetrated the general public remarkably well with an
  extensive network of associations and organizations of aficionados all
  over the world. Also, as a result of the huge amount of data accumulated
  and by necessity for their extensive international collaborations,
  astronomers have pioneered the development of distributed resources,
  electronic communications and networks coupled to advanced methodologies
  and technologies, often much before they become of common world-wide
  usage. This book is filling up a gap in the astronomy-related literature
  by providing a set of chapters not only of direct interest to astronomy
  communication, but also well beyond it. The experts contributing
  to this book have done their best to write in a way understandable
  to readers not necessarily hyperspecialized in astronomy nor in
  communication techniques while providing specific detailed information,
  as well as plenty of pointers and bibliographic elements. This book
  will be very useful for researchers, teachers, editors, publishers,
  librarians, computer scientists, sociologists of science, research
  planners and strategists, project managers, public-relations officers,
  plus those in charge of astronomy-related organizations, as well
  as for students aiming at a career in astronomy or related space
  science. <P />Link: <A href="http://www.wkap.nl/prod/b/1-4020-1345-0">
  http://www.wkap.nl/prod/b/1-4020-1345-0</A>

Title: Public Communication of Astronomy
Authors: Madsen, C.; West, R. M.
Bibcode: 2003ASSL..290....3M
Altcode: 2003asco.book....3M
  No abstract at ADS

Title: Breaking the ground for the European research area - The
    conference "European research 2002"
Authors: Madsen, C.
Bibcode: 2002Msngr.110...46M
Altcode:
  In the days November 11-13, about 9000 scientists, science
  administrators and policy makers gathered in Brussels to attend the
  Launch Conference for the ‘6th Framework Programme of the European
  Community for research, technological development and demonstration
  activities' - or for short, ‘FP-6'. While most participants came
  from the member states of the European Union, candidate countries and
  associated states, the meeting was in fact attended by people from
  65 countries, demonstrating the wide scope and the importance of the
  process set in motion to create the European Research Area. Some 50
  TV teams and 230 journalists from the print media covered the event,
  which El País, the leading Spanish newspaper, described as ‘The
  Science Summit in Brussels'. The strong media interest bears witness to
  the fact that science and technology (and with them, also education)
  are playing an increasingly important and visible role in the public
  sphere and that the organization and execution of research, as well
  as the exploitation of scientific results, are assuming importance in
  the mainstream political debate.

Title: Celebrating ESO's 40th anniversary
Authors: Madsen, C.
Bibcode: 2002Msngr.110...45M
Altcode:
  ESO has always been a forwardlooking organization, focussed on present
  and future programmes and projects. In its 40th year, this is as true
  as ever, as ESO keeps its eyes on implementing the VLTI, initiating the
  development of the second-generation instrumentation for the VLT and,
  of course, embarking on Phase II of the ALMA project, for which the ESO
  Council gave the green light at its midyear meeting in London. Still, a
  40th anniversary warrants a look at the decades passed and a reflection
  on the role and achievements of the organization during a period of
  time in which our science has progressed tremendously. That ESO has
  achieved its goals is undisputed, providing evidence of the wisdom of
  those astronomers who gathered in Leiden in early 1954 to formulate
  the need for this organization and justifying the trust displayed by
  the five countries, which were the original signatories to the 1962
  convention that formed the legal base for ESO.

Title: Forty years ESO - public anniversary activities
Authors: Madsen, C.
Bibcode: 2002Msngr.109...56M
Altcode:
  Readers of The Messenger will be well aware of ESO's 40th anniversary in
  October this year. This is most certainly a reason for ESO's friends to
  celebrate. Beyond the professional astronomers, engineers and other
  people with direct links to the organization, this includes many
  people all over Europe, e.g. amateur astronomers, science teachers,
  and people with a general interest in science. At the same time,
  the European Intergovernmental Research Organizations constitute fine
  examples of how, through collaboration, European countries can interact
  and achieve ambitious goals. Thus the success of ESO reaches beyond
  the confines of professional Astronomy.

Title: ESO in the European Parliament
Authors: Madsen, C.
Bibcode: 2002Msngr.108...43M
Altcode:
  Astronomy and Astrophysics is not normally at the centre of attention
  at the highest political circles in Europe. However, the renaissance
  that our science is currently experiencing, not least based on the
  spectacular success of the VLT, has not gone unnoticed among the
  decision makers in Europe.

Title: ESO Presentation in Brussels
Authors: Madsen, C.
Bibcode: 2001Msngr.106...48M
Altcode:
  No abstract at ADS

Title: Latest News: ESO High-Level Presentation in Porto
Authors: Madsen, C.
Bibcode: 2001Msngr.104...21M
Altcode:
  No abstract at ADS

Title: Success for ``Physics on Stage'' Festival in Geneva
Authors: Madsen, C.; West, R.
Bibcode: 2000Msngr.102...29M
Altcode:
  Can you imagine how much physics is in a simple match of ping-pong,
  in throwing a boomerang, or in a musical concert? Physics is all
  around us and governs our lives. But who is going to maintain these
  technologies and develop new ones in the future? Recent surveys show
  a frightening decline of interest in physics and technology among E
  u r o p e 's citizens, especially school children. Fewer and fewer
  young people enrol in physics courses at Europe's universities while
  scepticism towards science and technology is spreading and causing
  great concern among governments and educators.

Title: Public outreach in astronomy: The ESO experience
Authors: Madsen, C.; West, R. M.
Bibcode: 2000ASSL..250...25M
Altcode: 2000iha..conf...25M
  No abstract at ADS

Title: Science with the Atacama Millimetre Array
Authors: Madsen, C.
Bibcode: 1999Msngr..98...56M
Altcode:
  Science with the Atacama Large Millimetre Array

Title: ESO at the Hannover Fair
Authors: Madsen, C.
Bibcode: 1999Msngr..96...29M
Altcode:
  The Hannover Fair is the world's largest industrial fair. Each year
  more than 300,000 visitors from all over the world attend this major
  event which occupies 30 large exhibition halls. This year, about 7300
  enterprises from 63 countries demonstrated their latest products
  and services, either at individual stands or within ‘national'
  information stands.

Title: Award for the ESO VLT Project
Authors: Madsen, C.
Bibcode: 1998Msngr..94...38M
Altcode:
  Naturally, ‘First Light' for the first of the VLT Unit Telescopes
  has not gone unnoticed by the astronomical community. However, also
  newspapers, magazines, radio and TV have reported widely about this
  new facility and about the first, fascinating pictures that were
  obtained with UT1. Another sign of the world-wide attention that the
  VLT has caught was the fact that the well-known US magazine Popular
  Science chose the project for one of the coveted “The Best of What's
  New Awards” for 1998, given to the 100 most important technology
  developments in the course of the year. The construction of the VLT was
  recognised as an “outstanding achievement” within the “Aviation
  and Space” category.

Title: Sea &amp; Space - A Successful Educational Project for Europe's
    Secondary Schools
Authors: Madsen, C.; West, R.
Bibcode: 1998Msngr..93...44M
Altcode:
  There are many links between the Sea and the Space surrounding
  us. Indeed, Space itself is often likened with a new and uncharted
  Ocean on which we now continue the great voyages of discovery of the
  past. Space-based satellites allow us to study the processes in the
  Earth's oceans in unprecedented detail and at the same time to verify
  complex principles in fundamental sciences like physics, chemistry and
  mathematics. Space is also our tenuous link to the distant places from
  where the ingredients of life first came to our planet, and the ocean
  is where they began the incredible evolutionary processes of which we
  ourselves are a product.

Title: Astronomy On-Line - the World's Biggest Astronomy Event on
    the World-Wide-Web
Authors: Albrecht, R.; West, R.; Naumann, M.; Madsen, C.
Bibcode: 1998ASPC..145..248A
Altcode: 1998adass...7..248A
  This educational programme was organised in a collaboration between
  ESO, the European Association for Astronomy Education (EAAE) and the
  European Union (EU) during the 4th European Week for Scientific and
  Technological Culture. Astronomy On-Line brought together about 5000
  students from all over Europe and other continents. Learning to use
  the vast resources of tomorrow's communication technology, they also
  experienced the excitement of real-time scientific adventure and the
  virtues of international collaboration.

Title: ESO at the Leipzig fair
Authors: Madsen, C.
Bibcode: 1997Msngr..89...13M
Altcode:
  No abstract at ADS

Title: The astronomy on-line project.
Authors: West, R.; Madsen, C.
Bibcode: 1997Msngr..87...51W
Altcode:
  A major Web-based educational programme, known as Astronomy On-Line,
  has just taken place in close collaboration between the European
  Association for Astronomy Education (EAAE), the European Southern
  Observatory and the European Union.

Title: The King of Sweden Visits ESO Exhibition
Authors: Madsen, C.
Bibcode: 1996Msngr..84...36M
Altcode:
  No abstract at ADS

Title: ESO Exhibition in Florence
Authors: Madsen, C.
Bibcode: 1993Msngr..72...10M
Altcode:
  No abstract at ADS

Title: ESO at CNRS Plenary Meeting
Authors: Madsen, C.
Bibcode: 1993Msngr..72...12M
Altcode:
  No abstract at ADS

Title: "Exploring the Universe" from the Desert Gate
Authors: Madsen, C.
Bibcode: 1992Msngr..70...24M
Altcode:
  No abstract at ADS

Title: ESO exhibitions in Chile - a tremendous success.
Authors: Bouchet, P.; Cabillic, A.; Madsen, C.
Bibcode: 1992Msngr..68...18B
Altcode:
  No abstract at ADS

Title: ESO at Expo '92
Authors: Madsen, C.
Bibcode: 1992Msngr..67...48M
Altcode:
  No abstract at ADS

Title: Impressions from the XXI IAU General Assembly.
Authors: Baade, D.; Merkle, F.; Traat, P.; Sterken, C.; Grosbøl,
   P.; Rosa, M.; Madsen, C.; Warmels, R.; van der Laan, H.
Bibcode: 1991Msngr..65...17B
Altcode:
  No abstract at ADS

Title: Planeta Terra - Nosso Destino Comum
Authors: Madsen, C.
Bibcode: 1991Msngr..64...60M
Altcode:
  No abstract at ADS

Title: NGC 5084: a massive disc galaxy with a tilted ring.
Authors: Zeilinger, W. W.; Galletta, G.; Madsen, C.
Bibcode: 1990MNRAS.246..324Z
Altcode:
  Spectroscopic and photometric observations of the edge-on galaxy NGC
  5084 are presented and discussed. The galaxy exhibits a very faint outer
  structure which is is almost straight in projection, but is tilted by
  ~5^deg^ with respect to the brighter, inner stellar disc. Stellar and
  gas rotation curves at different position angles are presented, as well
  as accurate CCD surface photometry in Gunn i waveband. A geometrical
  analysis of the galaxy component is conducted on PDS tracings from ESO
  and ESO/SRC Sky Atlas copies. It is suggested that the tilt between
  the above components is due to the warping of the main galaxy plane,
  with the gas confined to a ring occupying its outer edge. If this is
  so, the apparent misalignment is only due to the lack of matter at
  intermediate radii. A three-component galaxy model has been used to
  correct the stellar rotation curve for the effects of integration along
  the line-of-sight and asymmetric drift. The resulting curve is in good
  agreement with the H I results in the outer parts. From this model, a 3D
  mass and light distribution has been derived and hence the mass-to-light
  ratio at various radii. This ratio varies from ~19 M_sun_/L_sun_ in
  the inner disc, up to ~45 M_sun_/L_sun_ in the outskirts, and there
  is a possible central peak with M/L &gt; 30 M_sun_/L_sun_. A massive,
  dark halo is required to explain the galaxy dynamics, which place NGC
  5084 among the supermassive disc galaxies. The presence of this dark
  halo offers a mechanism that could stabilize the warped disc. The
  possible external origin of the warped disc is discussed.

Title: BBC Makes ESO Film
Authors: Madsen, C.
Bibcode: 1990Msngr..59...20M
Altcode:
  BBC Makes ESO Film

Title: ESO at World Tech Vienna
Authors: Madsen, C.
Bibcode: 1989Msngr..57...33M
Altcode:
  No abstract at ADS

Title: Signposts of low mass star formation in molecular clouds.
Authors: Reipurth, B.; Madsen, C.
Bibcode: 1989Msngr..55...32R
Altcode:
  Regions of massive star formation are easily recognizable because
  of the presence of bright, often very extended H11 regions. The more
  quiescent places where only low mass star formation takes place are
  not so immediately obvious to identify. Most of the low mass star
  forming regions known today were found in the 1950's, mainly through
  objective prism surveys for Ha emission stars done by Joy, Herbig,
  Haro and others. Their results are summarized and supplemented by
  later findings in a new catalogue by Herbig and Bell (1988), which
  Iists 742 mainly low mass pre-main-sequence stars. Another recent
  and rich source of low mass young stars is the IRAS catalogue. IRAS
  data towards clouds, however, often suffer from source confusion and,
  in particular, extraction problems because of background emission.

Title: The Changing of Skyline of La Silla
Authors: Madsen, C.
Bibcode: 1989Msngr..55...31M
Altcode: 1989Msngr..55...31.
  The Changing of Skyline of La Silla

Title: Book-Review - Exploring the Southern Sky
Authors: Laustsen, S.; Madsen, C.; West, R. M.; Kutyrev, A. S.
Bibcode: 1988SvA....32..695L
Altcode:
  No abstract at ADS

Title: Book-Review - Exploring the Southern Sky - a Pictorial Atlas
    from the European Southern Observatory
Authors: Laustsen, S.; Madsen, C.; West, R. M.; Glass, I. S.
Bibcode: 1988MNSSA..47...58L
Altcode:
  No abstract at ADS

Title: Book-Review - Exploring the Southern Sky - a Pictorial Atlas
    from the European Southern Observatory
Authors: Laustsen, S.; Madsen, C.; West, R. M.; Bhatt, H. C.
Bibcode: 1988BASI...16..136L
Altcode:
  No abstract at ADS

Title: Book-Review - Exploring the Southern Sky - a Pictorial Atlas
    from the European Southern Observatory
Authors: Laustsen, S.; Madsen, C.; West, R. M.
Bibcode: 1988Sci...239Q1437L
Altcode:
  No abstract at ADS

Title: Book-Review - Exploring the Southern Sky - a Pictorial Atlas
    from the European Southern Observatory / ESO
Authors: Laustsen, S.; Madsen, C.; West, R. M.; Mitton, J.
Bibcode: 1988JBAA...98..114L
Altcode:
  No abstract at ADS

Title: Book-Review - Atlas of the Southern Hemisphere
Authors: Laustsen, S.; Madsen, C.; West, R. M.; Oleak, H.
Bibcode: 1988AN....309..345L
Altcode:
  No abstract at ADS

Title: A Deep High Resolution Wide Field Survey of the Milky Way
    (With 1 Figures)
Authors: Madsen, C.
Bibcode: 1988astr.conf..210M
Altcode:
  Generally speaking, objects in the Milky Way are probably the most
  observed astronomical objects. To obtain an overview of the Milky Way
  band, wide angle photography becomes necessary. Consequently a number
  of observers have produced wide angle photographs or full panoramas
  by making mosaics from several photographs. Most of the published
  photographs of the Milky Way band or parts thereof have been obtained
  in narrow pass-bands, such as Hα.

Title: Book-Review - Exploring the Southern Sky - a Pictorial Atlas
    from the European-Southern
Authors: Laustsen, S.; Madsen, C.; West, R. M.; Morrison, P.
Bibcode: 1988SciAm.258a.104L
Altcode: 1988SciAm.258..104L
  No abstract at ADS

Title: Deep LMC Images
Authors: West, R. M.; Pedersen, H.; Madsen, C.
Bibcode: 1987Msngr..50...24W
Altcode:
  One of the most observed objects in the southern sky is the Large
  Magellanic Cloud. It is easily seen as a naked-eye object near the
  southern celestial pole together with its less conspicuous neighbour,
  the Small Magellanic Cloud. Looking at the LMG, the casual observer
  discerns the elongated bar and the bright 30 Doradus nebula and,
  since February this year, the famous Supernova 1987 A.

Title: Book-Review - Exploring the Southern Sky
Authors: Laustsen, S.; Madsen, C.; West, R. M.; Hughes, D. W.
Bibcode: 1987Natur.330..618L
Altcode:
  No abstract at ADS

Title: Supernova 1987A in the Large Magellanic Cloud
Authors: West, R. M.; Madsen, C.; Bahcall, J.; Dar, A.; Piran, T.;
   Murdin, P.; Beresford, T.
Bibcode: 1987IAUC.4329....2W
Altcode: 1987IAUC.4329....1W; 1987IAUC.4329....0W
  R. M. West, European Southern Observatory, informs us that a color
  exposure (Agfachrome 1000 RS, Hasselblad 6 x 6) of the LMC was made by
  C. Madsen at La Silla during Feb. 23.042-23.056 UT. Sanduleak -69 202 is
  just seen near the limiting magnitude of about 12. J. Bahcall, A. Dar
  and T. Piran, Institute for Advanced Study, Princeton, communicate
  the following note, prepared in advance of the report of the neutrino
  detection on IAUC 4323: "We have calculated the event rate expected in
  terrestrial neutrino detectors from neutrinos produced in the formation
  of the neutron star in the LMC supernova. Using neutrino fluxes from a
  model stellar collapse calculation of Wilson et al. and cross sections
  from Bahcall, we estimate that only about one atom of Ar is produced in
  the Davis Cl tank, but that about 50 electron recoils, with energies of
  about 10 MeV, are produced in the Kamiokande II water detector. We also
  estimate about 3 events each in the scintillators of the University of
  Pennsylvania (Homestake Mine) and the Italian- Russian collaboration
  (Mont Blanc). The results are sensitive to the effective temperature of
  the emitted neutrino spectrum." P. Murdin, Royal Greenwich Observatory,
  reports: "It is not clear whether the relative constancy of the light
  curve of SN 1987A from Feb. 25 to Mar. 3 represents the maximum in a
  typical type II light curve or the 20 day premaximum halt seen in SN
  1940B and 1941A. If SN 1987A follows precedent, either it will decline
  soon to mag 6, where it will remain in the post-maximum plateau until
  early May, or it will brighten in mid-March to a maximum at mag about
  2, remaining brighter than mag 6 until early July. Observers should be
  aware of this uncertainty when planning observations." Visual magnitude
  estimate by T. Beresford, Adelaide, South Australia: Mar. 3.42 UT, 4.3.

Title: Wide angle photography of the Milky Way.
Authors: Madsen, C.; Laustsen, S.
Bibcode: 1986Msngr..46...12M
Altcode:
  Since astronomers began to use photography on a scientific basis,
  a number of pictures of the Milky Way band, or large parts thereof,
  has been made. Barnard (1890, 1927) produced a series of fine Milky
  Way photos. Later attempts by Rodgers, Whiteoak et al. (1960),
  Schmidt-Kaler and Schlosser (1972), Sivan (1974) and others resulted
  in impressive pictures, either in the form of panoramas or extreme
  wide-field views, mostly in weil defined (narrow) spectral bands. The
  most famous depietion of the Milky Way, however, is not a photograph
  but a drawing made by hand. This was made by M. and T. Keskula at
  Lund Observatory, and it has become the standard representation of
  the Milky Way band in textbooks.

Title: Some nonatlas work at the European Southern Observatory (ESO)
    Sky Atlas Laboratory
Authors: Madsen, C.
Bibcode: 1984asph.conf..143M
Altcode: 1984asph.rept..143M
  Black and white and color astronomical photography at the European
  Southern Observatory is described. For black and white copying, unsharp
  masking, diffuse light amplification (DLA), and integrated printing
  are used. To reduce noise in DLA plate surfaces, several enhanced
  derivatives are printed together. Color photographs are produced by
  contact printing. The application of false color composites for fast
  location of excess UV objects is described.

Title: Some non-atlas work at ESO Sky Atlas Laboratory.
Authors: Madsen, C.
Bibcode: 1984ORROE..14..143M
Altcode:
  The ESO Sky Atlas Laboratory (SAL) was set up in 1972 with the aim
  of producing the ESO Quick Blue Survey and later the joint ESO/SERC
  Survey of the Southern Sky. With the establishment of a Scientific
  Group, it became apparent that ESO had additional photographic needs,
  the fullfilment of which was also entrusted to SAL. Thus, in the course
  of the years, the "Photographic Section" evolved as a subdivision of
  the Sky Atlas Laboratory.

Title: Technical photography at ESO Sky Atlas Laboratory.
Authors: West, R. M.; Diebold, L.; Dumoulin, B.; Madsen, C.; Québatte,
   J.; Völk, E.; Zodet, H.
Bibcode: 1984ESOTR..14.....W
Altcode:
  No abstract at ADS

Title: Moderne photographische Kopiermethoden in der Astronomie
Authors: Madsen, C.
Bibcode: 1984MitAG..62..175M
Altcode:
  No abstract at ADS

Title: Tirage en couleur de photographies astronomiques à
    l'Observatoire Européen Austral.
Authors: Madsen, C.; Tarenghi, M.
Bibcode: 1983LAstr..97..376M
Altcode:
  No abstract at ADS

Title: A Dust lane in NGC 6251.
Authors: Nieto, J. -L.; Coupinot, G.; Lelievre, G.; Madsen, C.
Bibcode: 1983MNRAS.203P..39N
Altcode:
  A dust lane cutting the central region of the radio galaxy NGC 6251
  along its minor axis has been observed. This dust lane is roughly
  parallel to the radio jet. The implications of this observation are
  discussed: (1) NGC 6251 resembles a prolate object, morphologically
  at least. (2) Since the jet is remarkably linear, the configuration
  of the dust lane-stellar potential-nucleus system is probably quite
  stable. The dust lane may be responsible for the bending of the jet
  outwards. (3) Time-scale arguments relative to a possible merging
  suggest a rather slow non-relativistic motion. (4) The orientation of
  the dust lane does not support the suggestion by Kotanyi &amp; Ekers of
  a correlation between the axis of rotation of the gaseous disc and the
  jet axis in a radio galaxy, or of a correlation between the alignment
  of both rotation and jet axes with the power of the source.

Title: Fotografisk arbejde hos ESO.
Authors: Madsen, C.
Bibcode: 1983ATi....16..109M
Altcode:
  No abstract at ADS

Title: Astronomical Color Printing at ESO
Authors: Madsen, C.; Tarenghi, M.
Bibcode: 1982Msngr..30...15M
Altcode:
  When the photographic labs in the new Garching Headquarters were
  planned, the installation of a colour lab was also foreseen. Following
  the removal from Geneva, a market survey of available colour equipment
  was carried out, leading to the purchase of a Durst 1800 Laborator
  enlarger featuring a CLS 2000 colour head and a negative carrier able
  to accommodate 25 x 25 cm originals, an Autopan 40-60 C processing
  machine and various equipment for process control.

Title: On the reality of minor planet (330) Adalberta
Authors: West, R. M.; Madsen, C.; Schmadel, L. D.
Bibcode: 1982A&A...110..198W
Altcode:
  It is argued that the minor planet (330) Adalberta, as discovered
  photographically by Wolf in 1892, is nonexistent. It appears that the
  two positions of the planet refer to galactic stars which, mainly due
  to differences in the limiting magnitudes of the plates, simulated
  a moving object. It is proposed that (330) Adalberta be deleted from
  the minor planet list.

Title: Photographic Image Manipulation
Authors: Madsen, C.
Bibcode: 1982Msngr..28...19M
Altcode:
  The Messenger No. 25 contained a short, general description of
  the non-atlas work being done in the Sky Atlas Laboratory. Briefly
  mentioned in the article were contrast manipulating methods ranging
  from masking-to reduce the contrast of a picture--to contrast enhancing
  methods used to obtain printable negatives (or positives). Here the
  procedure, the advantages and the problems connected with masking and
  image amplification, will be described in some detail.

Title: (330) Adalberta
Authors: West, R. M.; Madsen, C.; Schmadel, L. D.; Wolf, M.
Bibcode: 1982IAUC.3672....2W
Altcode:
  R. M. West and C. Madsen, European Southern Observatory; and
  L. D. Schmadel, Astronomisches Rechen-Institut, inform us that this
  notorious minor planet, allegedly observed by M. Wolf on two nights
  only in 1892 March, does not exist. A careful reexamination of the
  original Heidelberg plates shows that Wolf's two measurements refer
  to galactic stars.

Title: Non-Atlas Photographic Work in the ESO Sky Atlas Laboratory
Authors: Madsen, C.
Bibcode: 1981Msngr..25...16M
Altcode:
  As is weil known to the readers of the MESSENGER, the ESO Sky Atlas
  Laboratory was established to set up and undertake the production of the
  ESO/SRC Sky surveys. To fulfil its duties, a number of dark rooms were
  set up and, after some years of hard work, techniques were developed
  which permit limited mass-production without sacrificing the quality
  which has become the hallmark of this project.

