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.

The Messenger is published twice per year and is available for free download as a PDF here and via the digital publishing platform Scribd.

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Issue 184
Messenger Issue 184

The Messenger Issue 184

Highlights include:

  • Williams, A., Hainaut, O. et al.: Analysing the Impact of Satellite Constellations and ESO’s Role in Supporting the Astronomy Community
  • Mérand, A., Andreani, P. et al.: Report on the Scientific Prioritisation Community Poll (2020)
  • Spiniello, C., Tortora, C. et al.: The INvestigate Stellar Population In RElics (INSPIRE) Project — Scientific Goals and Survey Design
  • Anderson, R., Suyu, S. et al.: Maintaining Scientific Discourse During a Global Pandemic: ESO’s First e-Conference #H02020

Read the full PDF

Past Issues
Messenger Issue 192
2024Issue 192
Messenger Issue 191
2023Issue 191
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 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
Table of Content No. 184 | 2021
Williams, A., Hainaut, O. et al.
Analysing the Impact of Satellite Constellations and ESO’s Role in Supporting the Astronomy Community
ADS BibCode: 2021Msngr.184....3W
Williams, A., Hainaut, O., Otarola, A., Tan, G., Rotola, G.
In the coming decade, up to 100 000 satellites in large constellations could be launched into low Earth orbit. The satellites will introduce a variety of negative impacts on astronomy observatories and science, which vary from negligible to very disruptive depending on the type of instrument, the position of the science target, and the nature of the constellation. Since the launch of the first batch of SpaceX’s Starlink constellation in 2019, the astronomy community has made substantial efforts to analyse the problem and to engage with satellite operators and government agencies. This article presents a short summary of the simulations of impacts on ESO’s optical and infrared facilities and ALMA, as well as the conducted observational campaigns to assess the brightness of satellites. It also discusses several activities to identify policy solutions at the international and national level.

Mérand, A., Andreani, P. et al.
Report on the Scientific Prioritisation Community Poll (2020)
ADS BibCode: 2021Msngr.184....8M
Mérand, A., Andreani, P., Cirasuolo, M., Comerón, F., De Gregorio Monsalvo, I., Dessauges-Zavadsky, M., Emsellem, É., Ivison, R., Kemper, F., Kerschbaum, F., Leibundgut, B., Liske, J., McLure, R., Mroczkowski, T., Origlia, L., Philips, N., Sana, H.
ESO regularly updates its science- driven perspective in order to provide the best facilities and services for its community. As part of this exercise, ESO polled its users between January and February 2020. Questions were inspired by the previous poll, conducted in 2015, to probe any evolution of community opinions and profile, with an emphasis on the future of the Very Large Telescope (VLT) and the VLT Interferometer (VLTI). Of the approximately 17700 registered users targeted, 10% had accounts in both the ESO and European ALMA portals, another 14% were registered in the ALMA portal only, and the remaining 76% were registered in the ESO portal only. Some 3700 email addresses, predominantly associated with the ESO portal, were invalid. From the remaining approximately 14000 user accounts, 1673 complete responses were received, a response rate comparable to that of the 2015 poll. The present poll was split into three parts: 1) profile of respondent; 2) current and future observing facilities; 3) ESO in the coming decade. Here we summarise the results and provide some highlights from the poll.

Zwaan, M., Hatziminaoglou, E. et al.
A Guide to ALMA Operations and Interactions with the Community
ADS BibCode: 2021Msngr.184...16Z
Zwaan, M., Hatziminaoglou, E., Kemper, F., Testi, L., Humpreys, E., Fukagawa, M., Remijan, A., Biggs, A., Díaz Trigo, M., Guglielmetti, F., van Kampen, E., Maud, L., Miotello, A., Petry, D., Popping, G., Randall, S., Stanke, T., Stoehr, F.
A primary goal of the Atacama Large Millimeter/submillimeter Array (ALMA) has always been to be a facility accessible to astronomers, radio-interferometry experts and non-experts alike. As a project, it is strongly committed to listening to its users and to utilising this input in decision making and priority setting. Feedback from the community often highlights the perceived complexity of ALMA’s organisational structure and, by extension, a diffuse uncertainty around how to make users’ voices heard. The aim of this article is to provide insight into the functioning of ALMA as an integrated observatory, with an emphasis on science and science operations. We present information on the ways the observatory communicates with the broader community, with a focus on the mechanisms by which the community can provide feedback to the project.

Quertier, B., Gauffre, S. et al.
Upgrade Strategies for the ALMA Digital System
ADS BibCode: 2021Msngr.184...20Q
Quertier, B., Gauffre, S., Randriamantena, A., Studniarek, M., De Breuck, C., Mroczkowski, T., Tan, G., Kemper, C., Phillips, N.
The Atacama Large Millimeter/submillimeter Array (ALMA) comprises 66 antennas working as a powerful interferometer. High-speed digitisation, signal transmission over several tens of kilometres from the receivers to the correlator, and complex data processing all require state-of-the-art technologies. The ALMA2030 Development Roadmap calls for an increase in the bandwidth by at least a factor of two, implying a major upgrade of the entire signal path. We present here the results of a detailed study looking at how to upgrade the ALMA digital system, including digitisation, data pre-processing, and data transmission to cope with bandwidths more than four times the current ones. At the same time, this system will contribute to increasing the nominal correlation efficiency from 88% to 99%, and prepare ALMA for longer baselines of up to 100 kilometres.

Spiniello, C., Tortora, C. et al.
The INvestigate Stellar Population In RElics (INSPIRE) Project — Scientific Goals and Survey Design
ADS BibCode: 2021Msngr.184...26S
Spiniello, C., Tortora, C., D’Ago, G., Napolitano, N., The INSPIRE Team
Relics are the ancient fossils of the early Universe. They are ultra-compact and massive galaxies that formed only a few (1–2) billion years after the Big Bang, in a short and intense burst of star formation, and then evolved passively and undisturbed until the present day, completely missing the accretion phase predicted for the assembly of local giant early-type galaxies. As such, they represent a unique opportunity to put precise constraints on the first phase of structure formation in the Universe. Since the number of relics predicted at each redshift depends heavily on the mechanisms responsible for the accretion and growth of massive galaxies, obtaining number counts at 0 < z < 0.5 is a very powerful way to validate and disentangle different possible physical scenarios driving their formation and size-evolution. INvestigating Stellar Population In RElics (INSPIRE) is an ongoing project based on an approved ESO Large Programme, targeting 52 relic candidates with the X-shooter spectrograph at ESO’s Very Large Telescope with the aim of building the first statistically large catalogue of relics at 0.1 < z < 0.5.

Anderson, R., Suyu, S. et al.
Maintaining Scientific Discourse During a Global Pandemic: ESO’s First e-Conference #H02020
ADS BibCode: 2021Msngr.184...31A
Anderson, R., Suyu, S., Mérand, A.
From 22 to 26 June 2020, ESO hosted its first live e-conference, #H02020, from within its Headquarters in Garching, Germany. Every day, between 200 and 320 participants around the globe tuned in to discuss the nature and implications of the discord between precise determinations of the Universe’s expansion rate, H0. Originally planned as an in-person meeting, we moved to the virtual domain to maintain strong scientific discourse despite the COVID-19 pandemic. Here we describe our conference setup, feedback gathered from participants before and after the meeting, and lessons learned from this unexpected exercise. As e-conferences will become increasingly common in the future, we provide our perspective on how they can make scientific exchanges more effective and inclusive, and also climate friendly.

Miles-Páez, P., Gentile Fusillo, N.
Fellows at ESO
ADS BibCode: 2021Msngr.184...37E
Miles-Páez, P., Gentile Fusillo, N.

Personnel Movements
ADS BibCode: 2021Msngr.184...39E