The Messenger

The Messenger is ESO’s journal for science and technology. It serves as a link between ESO and its broad astronomical community by providing information about scientific, technical, and other developments. It also delivers relevant news about astronomy and astrophysics to a broader public, including policy-makers, government officials, journalists, teachers, and amateur astronomers, as well as to interested scientists from other fields.

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Latest Issue
Messenger Issue 191

The Messenger Issue 191

Highlights include:

  • Barcons, X.: Sixty Years of Engagement Between ESO and Chile: Past, Present and Future
  • Bacon, R., Brinchmann, J. et al.: Scientific Highlights from Ten Years of the MUSE Collaboration
  • Romaniello, M., Arnaboldi, M. et al.: The ESO Science Archive Facility: Status, Impact, and Prospects

Read the full PDF

Past Issues
Messenger Issue 190
2023Issue 190
Messenger Issue 189
2022Issue 189
Messenger Issue 188
2022Issue 188
Messenger Issue 187
2022Issue 187
Messenger Issue 186
2022Issue 186
Messenger Issue 185
2021Issue 185
Messenger Issue 184
2021Issue 184
Messenger Issue 183
2021Issue 183
Messenger Issue 182
2021Issue 182
Messenger Issue 181
2020Issue 181
Messenger Issue 180
2020Issue 180
Messenger Issue 179
2020Issue 179
Messenger Issue 178
2019Issue 178
Messenger Issue 177
2019Issue 177
Messenger Issue 176
2019Issue 176
Messenger Issue 175
2019Issue 175
Messenger Issue 174
2018Issue 174
Messenger Issue 173
2018Issue 173
Messenger Issue 172
2018Issue 172
Table of Content No. 191 | 2023
The Organisation
Barcons, X.
Sixty Years of Engagement Between ESO and Chile: Past, Present and Future
ADS BibCode: 2023Msngr.191....3B
Barcons, X.
On 6 November 1963 ESO and the Republic of Chile started a journey together that enabled the establishment in Chile of all ESO’s observatories and telescopes so far. Despite all the challenges that the world went through over these six decades, a strong partner- ship between ESO and Chile has been forged. A vibrant user community in Chile has grown and matured, and ESO is proud to have accompanied this remarkable evolution. In this article I look at the past and present of the engagement between ESO and Chile and argue in favour of a future joint path.

Díaz Trigo, M., De Breuck, C. et al.
Ten Years of ALMA: Achievements and Future Perspectives
ADS BibCode: 2023Msngr.191....6T
Díaz Trigo, M., De Breuck, C., Hatziminaoglou, E., Rossi, S., Schmid, E., Zwaan, M.
This year marks the 10th anniversary of the inauguration of the Atacama Large Millimeter/submillimeter Array (ALMA), the world’s largest radio observatory. Over the past decade, ALMA, an international collaboration in which ESO, representing its Member States, is the European partner, has revolutionised our view of the Universe from the Solar System to the most distant galaxies. ALMA has produced iconic images that have attracted worldwide attention, such as that of the planet-forming disc around the young star HL Tau, and contributed to the first image of the shadow of a black hole at the heart of the galaxy M87. In this article we look back at the main achievements of ALMA and provide an outlook into the future.

Astronomical Science
Bacon, R., Brinchmann, J. et al.
Scientific Highlights from Ten Years of the MUSE Collaboration
ADS BibCode: 2023Msngr.191...11B
Bacon, R., Brinchmann, J., Bouché, N., Contini, T., Kamann, S., Krajnović, D., Monreal Ibero, A., Richard, J., Urrutia, T., Wisotzki, L., and the MUSE collaboration
We present the scientific highlights of ten years of exploitation of the Multi Unit Spectroscopic Explorer (MUSE) Guaranteed Time Observations performed in the context of the MUSE collaboration. These ten years have been particularly rich in discoveries and have resulted in more than 120 refereed papers. In this article we focus on the main results, grouped into four broad topical categories: resolved stellar populations, nearby galaxies, galaxy demographics, and the circumgalactic medium.

Meingast, S., Alves, J. et al.
The VISTA Star Formation Atlas (VISIONS)
ADS BibCode: 2023Msngr.191...18M
Meingast, S., Alves, J., Bouy, H., for the VISIONS collaboration
VISIONS is a public survey that explores five nearby star-forming molecular cloud complexes. The observing programme finished in March 2022, after collecting more than one million individual images in the near-infrared passbands J, H, and KS over a period of five years. VISIONS aims to provide a comprehensive legacy archive similar to the Two Micron All Sky Survey. In addition, multi-epoch observations facilitate proper motion measurements for sources inaccessible to Gaia. VISIONS addresses science cases related to the identification of young stars, their 3D motions, the evolution of embedded star clusters, and the characteristics of interstellar dust.

Telescopes and Instrumentation
Concas, A., Davies, R. et al.
ERIS Science Verifications
ADS BibCode: 2023Msngr.191...25C
Concas, A., Davies, R., Petr-Gotzens, M., Heida, M., Kuntschner, H., Leibundgut, B., Marsset, M., De Rosa, R., Tacconi-Garman, L., Wahhaj, Z., Wevers, T., Parraguez, D., Blanchard, I.
The Enhanced Resolution Imager and Spectrograph (ERIS) is the new near-infrared instrument at the Cassegrain focus of Unit Telescope 4 (UT4) of ESO’s Very Large Telescope. Its Science Verification (SV) was scheduled from 2 to 6 December 2022 during which time conditions were mostly good. Most of the planned SV observing programme could be accomplished. Out of 87 submitted proposals 23 observing programmes were scheduled for a total of 40 hours of observations. The allocation had assumed observations in four nights (eight hours each) and included a slight oversubscription. Five of the seven top-ranked proposals could be fully completed, the other two received partial data. In total, eleven programmes could be completed, seven were partially observed and three programmes could not be started. Some smaller technical problems with the adaptive optics affected parts of the observations.

Romaniello, M., Arnaboldi, M. et al.
The ESO Science Archive Facility: Status, Impact, and Prospects
ADS BibCode: 2023Msngr.191...29R
Romaniello, M., Arnaboldi, M., Barbieri, M., Delmotte, N., Dobrzycki, A., Fourniol, N., Freudling, W., Grave, J., Mascetti, L., Micol, A., Retzlaff, J., Rosse, N., Tax, T., Vuong, M., Hainaut, O., Rejkuba, M., Sterzik, M.
Scientific data collected at ESO’s observatories are freely and openly accessible online through the ESO Science Archive Facility. In addition to the raw data straight out of the instruments, the ESO Science Archive also contains four million processed science files available for use by scientists and astronomy enthusiasts worldwide. ESO subscribes to the FAIR (Findable, Accessible, Interoperable, Reusable) guiding principles for scientific data management and stewardship. All data in the ESO Science Archive are distributed according to the terms of the Creative Commons Attribution 4.0 International licence (CC BY 4.0).

Pritchard, J., Coccato, L. et al.
Telluric Correction of VLT Spectra: The New Graphical Interface to Molecfit
ADS BibCode: 2023Msngr.191...34P
Pritchard, J., Coccato, L., Freudling, W., Smette, A.
The removal of absorption features due to Earth’s atmosphere is a fundamental and delicate process in the reduction of spectroscopic observations, in particular in the near- and mid-infrared. In this paper we present the new graphical user interface of Molecfit, a package that aims to model the full atmospheric transmission by fitting key absorption features in spectra.

López-Fernández, I., Gallego, J. et al.
Ultra-wideband Cryogenic Low Noise Amplifiers: a Cool and Crucial Component for Future Submillimetre Radio Telescopes
ADS BibCode: 2023Msngr.191...37L
López-Fernández, I., Gallego, J., Diez, C., Malo, I., Amils, R., Tan, G.
This article reports on the evolution in designing state-of-the-art cryogenic, wideband, low-noise amplifiers as used in the intermediate frequency stages of ALMA receivers. The most recent designs are presented which demonstrate exceptional bandwidth and noise performance; those are crucial in enabling the planned ALMA Wideband Sensitivity Upgrade.

Emerson, J., Ivanov, V. et al.
VIRCAM Operations End at VISTA
ADS BibCode: 2023Msngr.191...42E
Emerson, J., Ivanov, V., Szeifert, T., Haeussler, B., Muñoz Mateos, J., Rejkuba, M., Arnaboldi, M., Petr-Gotzens, M., Hilker, M., Irwin, M., Cross, N.
The VISTA InfraRed CAMera (VIRCAM) at the Visible and Infrared Survey Telescope for Astronomy (VISTA) made its last observation on the night of 5/6 March 2023 after more than a decade of infrared surveys. Its place at VISTA’s focal plane is soon to be taken by the 4-metre Multi-Object Spectroscopic Telescope (4MOST) working in the visible region. Here we look back and summarise the experience gained and the great legacy of VIRCAM.

Astronomical News
de Gregorio-Monsalvo, I., Hilker, M. et al.
Celebrating 25 Years of Remarkable Science and Engineering with the VLT
ADS BibCode: 2023Msngr.191...47G
de Gregorio-Monsalvo, I., Hilker, M., Leibundgut, B.
Twenty-five years ago, on 25 May 1998, a significant milestone was reached for ESO and for European astronomy as the Very Large Telescope (VLT) captured its first images. On the occasion of its first light, the 8-metre Unit Telescope UT1 offered impressive images of our Universe. These included a successful tracking test in the globular cluster Omega Centauri, detailed images of the central region of another globular cluster, Messier 4, the fine structure of the Butterfly Nebula, high-velocity ejecta near Eta Carinae, and a captivating picture showcasing stars, dust, and gas in Centaurus A.

Guglielmetti, F., Mérand, A. et al.
Report on the ESO workshop: VLTI and ALMA Synthesis Imaging Workshop
ADS BibCode: 2023Msngr.191...50G
Guglielmetti, F., Mérand, A., Wittkowski, M., Tychoniec, L., González-Torà, G., Zwaan, M., Andreani, P., De Breuck, C.
Supported by the EU-funded Opticon RadioNet Pilot (ORP), the VLTI and ALMA Synthesis Imaging Workshop was held at ESO Headquarters on 9–12 January 2023. The hybrid format of the workshop allowed one hundred registered participants from six continents to gather, bringing with them a wide range of expertise: theorists, observers and data scientists. The need for such a broad range of skills originates in the workshop’s focus on interferometric image-reconstruction algorithms applied to data from instruments across the optical/infrared and millimetre/radio domain, allowing the diverse communities to build synergies and explore innovative techniques applicable to both regimes. The three-day workshop was organised into six topics, each followed by discussion. Four distinguished lecturers established a shared understanding of data analysis processes (including data characteristics, handling and reduction) and presented innovative techniques employing artificial intelligence used by the two communities. Traditional imaging methods, as well as techniques for morphology fitting and other popular tools and methods, were presented and discussed by keynote speakers. Given the nature and goals of the workshop, most of the speakers were invited. ORP supported a number of speakers as well as students to allow growth within a young community in the rapidly evolving area of image analysis.

Mérand, A., Cirasuolo, M. et al.
Report on the ESO workshop: Disks and Planets across ESO Facilities
ADS BibCode: 2023Msngr.191...56M
Mérand, A., Cirasuolo, M., Díaz Trigo, M., Leibundgut, B.
The observation of protoplanetary discs and exoplanets is a relatively recent and rapidly evolving research field. Many questions are still being posed, driven by both observations and theoretical developments. Discs and exoplanets now constitute a central observational field in astrophysics, and one of the main motivations for ESO and its community to build the Atacama Large Millimeter/submillimeter Array and the Extremely Large Telescope. They are also behind many recent and future developments at the Paranal and La Silla observatories. A workshop was held at ESO Headquarters in November/December 2022 to reflect on the role of ESO facilities (present and future) in this landscape.

Bodensteiner, J., Kaasinen, M. et al.
Fellows at ESO
ADS BibCode: 2023Msngr.191...58E
Bodensteiner, J., Kaasinen, M., Berton, M.