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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Issue 188
Messenger Issue 188

The Messenger Issue 188

Highlights include:

  • Barcons, X.: ESO at 60: Looking Forward
  • Murphy, M., Molaro, P. et al.: ESPRESSO Probes the Fine-structure Constant
  • Cristiani, S., Alcalá, J. et al.: CUBES, the Cassegrain U-Band Efficient Spectrograph for the VLT

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 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
Table of Content No. 188 | 2022
The Organisation
Barcons, X.
ESO at 60: Looking Forward
ADS BibCode: 2022Msngr.188....3B
Barcons, X.
After a very successful 60 years of challenges and achievements, ESO is an organisation enabling fascinating astronomical discoveries with a broad portfolio of world-leading telescopes and instruments. The ESO business model has consolidated itself as a remarkable success. In this article I review where ESO stands today, attempting to understand what the keys to its success are, and I set out some views about where the organisation should head in order to capitalise on its strengths.

Astronomical Science
Murphy, M., Molaro, P. et al.
ESPRESSO Probes the Fine-structure Constant
ADS BibCode: 2022Msngr.188...15M
Murphy, M., Molaro, P., Schmidt, T., Martins, C., da Fonseca, V., Milaković, D., Cupani, G., Cristiani, S., D’Odorico, V., Barreiro, T., Génova Santos, R., Leite, A., Marques, C., Nunes, N., Pepe, F., Rebolo, R., Santos, N., Sousa, S., Zapatero Osorio, M., Amate, M., Adibekyan, V., Alibert, Y., Allende Prieto, C., Baldini, V., Benz, W., Bouchy, F., Cabral, A., Dekker, H., Di Marcantonio, P., Ehrenreich, D., Figueira, P., González Hernández, J., Landoni, M., Lovis, C., Lo Curto, G., Manescau, A., Mégevand, D., Mehner, A., Micela, G., Pasquini, L., Poretti, E., Riva, M., Sozzetti, A., Suárez Mascareño, A., Udry, S., Zerbi, F.
The Echelle SPectrograph for Rocky Exoplanet and Stable Spectroscopic Observations (ESPRESSO) is the new high-resolution spectrograph of ESO’s Very Large Telescope. It was designed for ultra-high radial-velocity precision and extreme spectral fidelity with the aim of performing exoplanet research and fundamental astrophysical experiments with unprecedented precision and accuracy. The first precise ESPRESSO constraint on cosmological variations in the fine-structure constant has been obtained recently by using the laser frequency comb to provide a highly accurate wavelength scale. The target was the famous quasar HE 0515-4414, one of the brightest in the southern sky, with an intervening galaxy at z = 1.15 which imprints metal absorption lines onto the spectrum. The lack of velocity shifts between these lines is consistent with the absence of cosmological variation in the fine-structure constant at the level of about 1 part per million.

GRAVITY Collaboration, Sturm, E. et al.
The Core of the Matter — Spatially Resolving Active Galactic Nuclei with GRAVITY
ADS BibCode: 2022Msngr.188...20S
GRAVITY Collaboration, Sturm, E., Cao, Y., Clenet, Y., Davies, R., Dexter, J., Eckart, A., Eisenhauer, F., Genzel, R., Gratadour, D., Hönig, S., Kishimoto, M., Lacour, S., Lutz, D., Millour, F., Netzer, H., Perrin, G., Peterson, B., Petrucci, P., Pfuhl, O., Prieto, M., Rouan, D., Santos, D., Shangguan, J., Shimizu, T., Stock, M., Waisberg, I., Woillez, J., de Zeeuw, T., Amorim, A., Brandner, W., Garcia, P., Gillessen, S., Förster Schreiber, N., Ott, T., Paumard, T., Perraut, K., Straubmeier, C., Tacconi, L., Sternberg, A., Tristram, K.
Thanks to the superb sensitivity and resolution of GRAVITY, ESO’s near-infrared beam combiner for the Very Large Telescope Interferometer, our Large Programme study of the inner regions of active galactic nuclei (AGN) has delivered several recent breakthroughs. We have spatially resolved the broad line region (BLR) for three nearby AGN, supporting the rotating disc model, directly measuring the masses of their supermassive black holes (SMBHs), and testing the BLR radius-luminosity (R-L) scaling relation. We have measured the hot dust sizes for eight AGN and fully imaged the hot dust structure for two AGN. Our dust sizes also test the hot dust R-L scaling relation, revealing the first evidence for luminosity-dependent deviations from the expected relation. The novel GRAVITY data provide unique insight into the physics around SMBHs. In addition, they test the basic assumptions behind mass measurements based on the R-L scaling relation and reverberation mapping, which is currently the only method for measuring black hole masses in large surveys and out to high redshift. Our observations provide an entirely new, independent method for measuring SMBH masses. With GRAVITY+, we will be able to vastly expand to both larger samples and higher redshifts with the ultimate goal of tracing black hole growth and galaxy coevolution through cosmic time.

Merle, T., Hamers, A. et al.
HD 74438: a Young Spectroscopic Quadruple as a Possible Progenitor of Supernovae Ia
ADS BibCode: 2022Msngr.188...26M
Merle, T., Hamers, A., Van Eck, S., Jorissen, A., Van der Swaelmen, M., Pollard, K., Smiljanic, R., Pourbaix, D., Zwitter, T., Traven, G., Gilmore, G., Randich, S., Gonneau, A., Hourihane, A., Sacco, G., Worley, C.
Type Ia supernovae (SN Ia) are amongst the most energetic events in the Universe. They are used as standard candles to measure cosmological distances and they produce a rich nucleosynthesis; they are fundamental objects to understand the chemical evolution of galaxies. It is thought that SN Ia are produced by processes occurring in tight binaries including at least one carbon–oxygen white dwarf (WD). Such binaries could emerge from the dynamical evolution of high-multiplicity stellar systems such as the young spectroscopic quadruple HD 74438, recently detected in the Gaia–ESO Survey. Follow-up spectroscopic observations in South Africa and New Zealand, as well as the use of archival ESO spectra, allow us to characterise its orbital and astrophysical parameters. Modelling the dynamical evolution of stellar quadruples shows that such systems can produce WD mergers, possible progenitors of SN Ia.

Telescopes and Instrumentation
Massardi, M., Stoehr, F. et al.
Overview of the Additional Representative Images for Legacy (ARI-L) Development Project for the ALMA Science Archive
ADS BibCode: 2022Msngr.188...31M
Massardi, M., Stoehr, F., Bendo, G., Bonato, M., Brand, J., Galluzzi, V., Guglielmetti, F., Knapic, C., Liuzzo, E., Marchili, N., Richards, A., Rygl, K.
The Additional Representative Images for Legacy (ARI-L) project is a European Development project for ALMA Upgrade approved by the Joint ALMA Observatory and ESO in 2019. It aims to increase the legacy value of the ALMA Science Archive by bringing the reduction level of ALMA data from Cycles 2 to 4 close to that of data from more recent cycles processed for imaging with the ALMA Pipeline. To date, ARI-L has produced, assessed the quality of, and delivered more than 150000 images. These represent more than 85% of the science datasets from Cycles 2 to 4 processable with the ALMA Pipeline but lacking pipeline-generated images, and accordingly the project accomplished all its goals during its official runtime.

Cristiani, S., Alcalá, J. et al.
CUBES, the Cassegrain U-Band Efficient Spectrograph for the VLT
ADS BibCode: 2022Msngr.188...36C
Cristiani, S., Alcalá, J., Alencar, S., Avila, G., Balashev, S., Bastian, N., Barbuy, B., Battino, U., Calcines, A., Calderone, G., Cambianica, P., Carini, R., Carter, B., Cassisi, S., Castilho, B., Cescutti, G., Christlieb, N., Cirami, R., Coretti, I., Cooke, R., Covino, S., Cremonese, G., Cunha, K., Cupani, G., da Silva, A., De Caprio, V., De Cia, A., Dekker, H., D’Elia, V., De Silva, G., D’Auria, D., D’Odorico, V., Diaz, M., Di Marcantonio, P., Fitzsimmons, A., Ernandes, H., Evans, C., Franchini, M., Genoni, M., Gänsicke, B., Gneiding, C., Giribaldi, R., Grazian, A., Hansen, C., La Forgia, F., Landoni, M., Lazzarin, M., Lunney, D., Maciel, W., Marcolino, W., Marconi, M., Migliorini, A., Miller, C., Noterdaeme, P., Opitom, C., Pariani, G., Pilecki, B., Piranomonte, S., Quirrenbach, A., Redaelli, E., Pereira, C., Randich, S., Rossi, S., Sanchez-Janssen, R., Seifert, W., Smiljanic, R., Snodgrass, C., Squalli, O., Stilz, I., Stürmer, J., Trost, A., Vanzella, E., Ventura, P., Verducci, O., Waring, C., Watson, S., Wells, M., Wright, D., Zafar, T., Zanutta, A.
CUBES, the Cassegrain U-Band Efficient Spectrograph, aims to bring a unique capability to ESO’s Very Large Telescope: an ultraviolet eye on the Universe to complement the Extremely Large Telescope, a super-efficient (> 40%) spectrograph with a spectral coverage of 300–405 nm in the present design and two resolution modes, 20000 and 7000. An option of a fibre link to the Ultraviolet and Visual Echelle Spectrograph is foreseen that will provide the capability of simultaneous optical high-resolution spectroscopy at λ > 420 nm. The CUBES design is able to address a treasure trove of scientific cases, from Solar System science to cosmology.

Astronomical News
Popping, G., Manara, C. et al.
Interactions with the ESO Community During and After a Pandemic
ADS BibCode: 2022Msngr.188...43P
Popping, G., Manara, C., Hatziminaoglou, E., Pritchard, J., Boffin, H., Rejkuba, M., Zwaan, M., Ahmadi, A., Barta, M., Bendo, G., Bertoldi, F., Brand, J., Grossova, R., Hogerheijde, M., Immer, K., Impellizzeri, V., König, S., Liuzzo, E., Marchetti, T., Massardi, M., Maud, L., Miles-Páez, P., Moravec, E., Mühle, S., Paladino, R., Petr-Gotzens, M., Toribio, C.
To accomplish its mission, ESO puts significant effort into supporting its scientific community to allow broad access to ESO’s telescopes and to exploit its full technical and scientific capabilities. The pandemic-related challenges of the last few years have led to new ways of interacting with and providing support to the European ALMA and La Silla Paranal astronomical communities. Here we present some of the main events that have been organised in the last two years to achieve this goal, what we have learned, and how we foresee this will impact the future of interactions with the ESO users community.

Gadotti, D., Valenti, E. et al.
Report on the ESO Workshop "Inward Bound: Bulges from High Redshifts to the Milky Way"
ADS BibCode: 2022Msngr.188...47G
Gadotti, D., Valenti, E., Fragkoudi, F., Zanella, A., Coccato, L., de Sá Freitas, C., Chasiotis-Klingner, S.
With over 200 registered participants, this fully online conference allowed theorists and observers across the globe to discuss recent findings on the central structures of disc galaxies. By design, this conference included experts on the Milky Way, local and high-redshift galaxies, and theoretical aspects of galaxy formation and evolution. The need for such a broad range of expertise stems from the important advances that have been made on all fronts in recent years. One of the main goals of this meeting was accordingly to bring together these different communities, to find a common ground for discussion and mutual understanding, to exchange ideas, and to efficiently communicate progress.

Zeegers, S., Scicluna, P.
Report on the ESO Workshop "Reproducibility and Open Science in Astronomy"
ADS BibCode: 2022Msngr.188...50Z
Zeegers, S., Scicluna, P.
Reproducible and open research lies at the heart of science, for both practical and philosophical reasons. To validate results, researchers must be able to access the data and software used to produce them. Meanwhile, as a public good, the outcomes of (publicly-funded) research should be freely available. These were the main topics of the ESO workshop Reproducibility and Open Science in Astronomy, which was held online on 10–12 May 2022, hosted in Santiago, Chile. The goal of the workshop was to discuss the relevance of reproducible workflows in astronomy and potential pathways for the astronomical community. During the workshop the speakers and participants shared examples of reproducible work as well as tools and techniques for improving reproducibility and for mining astronomical data. All talks, tutorials and discussion sessions were recorded and can be viewed online.

Alcalde Pampliega, B., Tychoniec, Ł.
Fellows at ESO
ADS BibCode: 2022Msngr.188...53E
Alcalde Pampliega, B., Tychoniec, Ł.