The Messenger

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Highlights include:

Bonaldi, A., Zwaan, M. et al.: SKAO, SKA Precursors/pathfinders and ESO Facilities
Breen, S., Schödel, R. et al.: ESO–SKAO Coordinated Surveys: the Galaxy
Prandoni, I., Sargent, M. et al.: An ESO–SKAO Synergistic Approach to Galaxy Formation and Evolution Studies
Santos, M., Camera, S. et al.: Cosmology with ESO–SKAO Synergies
Mesinger, A., Ciardi, B. et al.: ESO–SKAO Synergies for the Epoch of Reionisation and Cosmic Dawn
Patat, F., Leibundgut, B. et al.: Yearly Call and Fast Track Channel at ESO

ADS BibCode: 2024Msngr.193....5B

Bonaldi, A., Zwaan, M., Best, P., Broderick, J., Goedhart, S., Mahony, E.

In The Messenger 192 a short report was published on the ESO–SKAO workshop Coordinated Surveys of the Southern Sky, which was held at ESO in Garching in early 2023. An important goal of this workshop was to publish a collection of articles that describe in some detail what existing synergetic science would be possible with well-planned coordinated surveys using ESO and SKAO facilities. The other four articles in this edition of The Messenger, covering respectively the Galaxy, galaxy formation and evolution, cosmology, and the epoch of reionisation and cosmic dawn, present such synergies and promising ways forward, and serve as references for ESO–SKAO coordinated surveys. By way of introduction, this article describes the SKAO and SKA precursor/pathfinder facilities and also briefly highlights the current and future ESO instrumentation that will be of particular importance for such coordinated surveys of the southern sky.

ADS BibCode: 2024Msngr.193....9B

Breen, S., Schödel, R., Ilee, J., Hoare, M., Thompson, M., Bianchi, E., Codella, C., Podio, L., Forbrich, J., Ingallinera, A., Bordiu, C., Brunthaler, A.

Our Galaxy occupies a special place in astrophysics, because it allows us to observe fundamental phenomena at least four orders of magnitude fainter and at physical scales at least 100 times smaller than in any other comparable galaxy. Observations of the Milky Way therefore provide the fundamental data for our understanding of processes such as star and planet formation, the physics of accretion and ejection, interstellar chemistry or the interaction of the interstellar medium, stars and a massive black hole as it occurs in galaxy nuclei. In this article we discuss accretion and ejection in star formation, carbon chemistry, unidentified radio sources in the Milky Way, Galactic structure, and stellar remnants in the Galactic centre as exemplary science cases where multiwavelength observations with the SKAO and ESO facilities can make a profound impact. We also briefly discuss the nature of the coordinated observations and any requirements that we consider necessary to carry them out successfully.

ADS BibCode: 2024Msngr.193...14P

Prandoni, I., Sargent, M., Adams, E., Catinella, B., Cirasuolo, M., Emsellem, E., Hopkins, A., Maddox, N., Mainieri, V., Wisnioski, E., Colless, M.

We highlight the potential benefits of a synergistic use of SKAO and ESO facilities for galaxy evolution studies, focusing on the role that ESO spectroscopic surveys can play in supporting next-generation radio continuum and atomic hydrogen (HI) surveys. More specifically we illustrate the role that currently available or soon to be operational ESO multiplex spectrographs can play for three classes of projects: large/deep redshift survey campaigns, integral field unit/Atacama Large Millimeter/submillimeter Array (IFU/ALMA) surveys of selected regions of sky, and IFU/ALMA follow-ups of selected samples. We conclude with some general recommendations for an efficient joint exploitation of ESO–SKAO surveys.

ADS BibCode: 2024Msngr.193...20S

Santos, M., Camera, S., Chen, Z., Cunnington, S., Fonseca, J.

We discuss the possible synergies for cosmology between SKAO and ESO facilities, focusing on the combinations SKA-Mid with the Multi-Object Spectrograph Telescope (4MOST) instrument built for ESO’s Visible and Infrared Survey Telescope for Astronomy (VISTA) and SKA-Low with ESO's Extremely Large Telescope (ELT) multi-object spectrograph MOSAIC. Combining multiple tracers allows for tackling systematics and lifting parameter degeneracies. It will play a crucial role in the pursuit of precision cosmology.

ADS BibCode: 2024Msngr.193...24M

Mesinger, A., Ciardi, B., Davies, J., Gagnon-Hartman, S., D’Odorico, V.

Mapping out the first billion years using the 21-cm line with the Square Kilometre Array (SKA) will revolutionise our understanding of the cosmic dawn, reionisation and the galaxies that drove these milestones. However, synergies with other telescopes in the form of cross-correlations will be fundamental in making and confirming initial, low signal-to-noise claims of a detection. Participants in the 2023 ESO–SKAO workshop discussed such synergies for Epoch of Reionisation (EoR) and Cosmic Dawn (CD) science. Here we highlight some of the most promising candidates for cross-correlating SKA EoR/CD observations with ESO instruments such as the Multi-Object Optical and Near-infrared Spectrograph (MOONS), the MOSAIC multi-object spectrograph, and the ArmazoNes high Dispersion Echelle Spectrograph (ANDES).

ADS BibCode: 2024Msngr.193...31T

Tortora, C., Ragusa, R., Gatto, M., Spavone, M., Hunt, L., Ripepi, V., Dall’Ora, M., Abdurro’uf, Annibali, F., Baes, M., Belfiore, F., Bellucco, N., Bolzonella, M., Cantiello, M., Dimauro, P., Kluge, M., Lelli, F., Napolitano, N., Nucita, A., Radovich, M., Scaramella, R., Schinnerer, E., Testa, V., Unni, A.

The VLT Survey Telescope Survey of Mass Assembly and Structural Hierarchy (VST-SMASH) aims to detect tidal features and remnants around very nearby galaxies, a unique and essential diagnostic of the hierarchical nature of galaxy formation. Leveraging optimal sky conditions at ESO’s Paranal Observatory, combined with the VST’s multi-band optical filters, VST-SMASH aims to be the definitive survey of stellar streams and tidal remnants in the Local Volume, targeting a low surface-brightness limit of μ ~ 30 mag arcsec^–2 in the g and r bands, and μ ~ 28 mag arcsec^–2 in the i band, in a volume-limited sample of local galaxies within 11 Mpc and the Euclid footprint.

ADS BibCode: 2024Msngr.193...37A

GRAVITY+ Collaboration, Abuter, R., Allouche, F., Amorim, A., Bailet, C., Berger, J., Berio, P., Bigioli, A., Boebion, O., Böttcher, R., Bolzer, M., Bonnet, H., Bourdarot, G., Bourget, P., Brandner, W., Brara, A., Clénet, Y., Courtney-Barrer, B., Davies, R., Defrère, D., Delboulbé, A., Delplancke, F., Dembet, R., Dong, S., Drescher, A., Eckart, A., Édouard, C., Eisenhauer, F., Fabricius, M., Feuchtgruber, H., Finger, G., Förster Schreiber, N., Frahm, R., Garcia, E., Garcia, P., Gendron, E., Genzel, R., Gil, J., Gillessen, S., Gomes, T., Gonté, F., Gopinath, V., Graf, J., Guajardo, P., Guieu, S., Häberle, M., Hartl, M., Haubois, X., Haußmann, F., Henning, T., Hönig, S., Horrobin, M., Hubin, N., Jochum, L., Jocou, L., Kaufer, A., Kervella, P., Kreidberg, L., Lacour, S., Lagarde, S., Lai, O., Lapeyrère, V., Laugier, R., Le Bouquin, J., Leftley, J., Léna, P., Lutz, D., Mang, F., Mérand, A., Millour, F., More, N., Mroz, P., Nowacki, H., Nowak, M., Neumayer, N., Oberti, S., Ott, T., Özdemir, H., Pallanca, L., Paumard, T., Perraut, K., Perrin, G., Petrov, R., Pfuhl, O., Pourré, N., Prowatke, H., Rabien, S., Rau, C., Rehm, C., Riquelme, M., Robbe, S., Rochat, S., Salman, M., Sauter, J., Schubert, J., Schuhler, N., Shangguan, J., Shimizu, T., Scheithauer, S., Schuppe, D., Soulez, F., Stadler, E., Straubmeier, C., Sturm, E., Subroweit, M., Sykes, C., Tacconi, L., Tristram, K., Vincent, F., Uysal, S., Wessely, P., Widmann, F., Wieprecht, E., Wiezorrek, E., Wimmer, L., Woillez, J., Yazici, S., Zins, G.

One of the primary goals of the GRAVITY+ upgrade is to significantly improve the sky coverage of GRAVITY and the Very Large Telescope Interferometer. With the successful commissioning and start of operations of the GRAVITY-Wide mode and the new Beam Compressor Differential Delay Lines, GRAVITY+ has opened up the sky to deep interferometric observations. These include the first dynamical black hole mass measurements at cosmic noon, vastly increased observable samples of microlensing events, and a step towards the first detection of an intermediate-mass black hole through stellar orbits.

ADS BibCode: 2024Msngr.193...45P

Patat, F., Leibundgut, B., Mieske, S., Rejkuba, M.

The Time Allocation Working Group (TAWG), formed in 2015 as one of the actions generated by the ESO 2020 prioritisation initiative, was tasked with reviewing the telescope time allocation process at ESO. The TAWG report outlined key recommendations aimed at enhancing the efficiency and effectiveness of proposal handling and telescope scheduling at ESO. Among these, the transition to a yearly cycle for the Call for Proposals and the introduction of a Fast Track Channel were highlighted as significant steps forward. This paper outlines the background, rationale, and next steps for these upcoming changes, made possible thanks to recent improvements in software and scheduling tools.

ADS BibCode: 2024Msngr.193...47M

Mieske, S., de Gregorio-Monsalvo, I., Anderson, J., Saviane, I., Rejkuba, M.

ESO operates its observatories in the Chilean Atacama Desert, far from large light-polluting cities. At the same time, there is a rich scientific life on the ESO campus in Santiago de Chile, with more than 30 faculty astronomers, two dozen postdoctoral fellows and around 10 PhD students. This makes ESO’s hub in Chile an excellent location to foster scientific collaborations, and a natural starting point to interact with the Chilean astronomical community. Here we summarise the numerous opportunities for astronomers to visit ESO in Chile and connect with its scientific ecosystem.

ADS BibCode: 2024Msngr.193...50R

Rodler, F., De Rosa, R., Johnston, E., Lucertini, F., Sbordone, L., Sedaghati, E.

The La Silla Observing School is a series of training workshops in the use of telescopes and astronomical instruments for students and early-career researchers in astronomy. Following schools in 2016, 2018 and 2020, the fourth La Silla Observing School was held over two weeks in February 2024 and was hosted by ESO’s Office for Science and the La Silla Observatory. A total of 20 MSc students, PhD students and postdoctoral researchers from South and North America, Europe and Australia participated. They attended lectures on various observing strategies and astronomical instrumentation, on diversity, equity and inclusion in astronomy, as well as soft skills. For the hands-on part at the observatory, the students were supervised by five tutors. Four small research projects were offered, using three telescopes and four instruments. The students in each research group went through the full process of defining and discussing the observing strategies, conducting the observations, reducing and analysing the data and finally presenting the results to the scientific community at the ESO Vitacura offices. Given the high demand from the astronomical community for such educational programs, ESO is currently exploring the possibility of offering the La Silla Observing School on a yearly basis. Accordingly, the next school is foreseen for February 2025.

ADS BibCode: 2024Msngr.193...54P

Petr-Gotzens, M., Häußler, B.

A decade of targeted wide-field imaging at ESO was coming to an end in early 2023, when the near-infrared imager VIRCAM at the Visible and Infrared Survey Telescope for Astronomy was decommissioned. Shortly before, in October 2022, the optical wide-field imager OmegaCAM at the VLT Survey Telescope had become a hosted telescope after many years of being an ESO-operated optical survey machine. The two instruments were largely dedicated to public imaging surveys, which have amassed a total of nearly 60 000 hours of telescope time. To commemorate these milestones, ESO organised a five-day workshop in October 2023 to review the legacy left by these instruments, to summarise the variety of scientific impacts that the imaging surveys have had on a wide range of research topics in astronomy, and to encourage new ideas from/within the community to enlarge the exploitation of the high-quality VIRCAM and OmegaCAM survey data.

ADS BibCode: 2024Msngr.193...57T

Díaz Trigo, M., Brogan, C., Carpenter, J., Hatsukade, B.

In December 2012 the first results from Early Science observations by the ALMA Observatory were discussed at a workshop held in Puerto Varas, Chile. In 2013 ALMA was inaugurated and only ten years later it has revolutionised our view of the Universe, both near and far. In December 2023 the scientific community returned to Puerto Varas to attend the conference ALMA at ten years: Past, Present and Future, celebrating ten years of ALMA operations. In this article, we report on the outcome of this conference.

ADS BibCode: 2024Msngr.193...61S

This workshop aimed to bring together the various communities of astronomers who observe the changing night sky, from studies of nearby moving targets to the most distant transient sources. All of these fields will soon enter a new era of discovery with the beginning of the LSST, and many of the most exciting science cases will need detailed follow-up observations (for example spectroscopic characterisation), which will place significant demands on ESO’s facilities. Participants at the workshop discussed the how, why, and when of obtaining ESO observations to find out ‘what was that?’, in the era of millions of alerts per night.

ADS BibCode: 2024Msngr.193...64E

Marsset, M., Barnes, A.

ADS BibCode: 2024Msngr.193...66E

The Messenger Issue 193