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.

If you wish to receive the new issue directly into your inbox, sign up here:
Issue 173
Messenger Issue 173

The Messenger Issue 173

Highlights include:

  • Rejkuba, M., Tacconi-Garman, L. et al.: Should I stay, or should I go? Service and Visitor Mode at ESO’s Paranal Observatory
  • Hainaut, O., Meech, K. et al.: Rendezvous with `Oumuamua
  • Clark, S., Lohr, M. et al.: Life at the Extremes — Massive Star Formation and Evolution in the Galactic Centre
  • Calistro Rivera, G., Hodge, J.: Resolving the Interstellar Medium at the Peak of Cosmic Star Formation

Read the full PDF

Past Issues
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 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 172
2018Issue 172
Table of Content No. 173 | 2018
Telescopes and Instrumentation
Rejkuba, M., Tacconi-Garman, L. et al.
Should I stay, or should I go? Service and Visitor Mode at ESO’s Paranal Observatory
ADS BibCode: 2018Msngr.173....2R
Rejkuba, M., Tacconi-Garman, L., Mieske, S., Anderson, J., Gadotti, D., Marteau, S., Patat, F.
Since the beginning of Very Large Telescope (VLT) operations in 1998, ESO has been offering time in both Visitor Mode (VM) and Service Mode (SM). In this article we discuss the advantages and limitations of these two observing modes, explain the rationale behind the one-hour observation rule in SM, and provide some statistics comparing the usage in each mode. Community demand has been steadily growing for SM observations and is now above 80% for normal programmes (i.e., not Large or Guaranteed Time Observation programmes). Here, we highlight the benefits of VM and promote its usage to the community. We also emphasise the low demand for SM for observations in the most demanding seeing conditions.

Patat, F.
The Time Allocation Working Group Report
ADS BibCode: 2018Msngr.173....7P
Patat, F.
A Time Allocation Working Group was charged with the task of reviewing the telescope time allocation process at ESO. The working group submitted a report to the Director for Science, including a set of recommendations and suggestions for an implementation plan. This paper gives a general overview of the recommendations and a status report on their implementation.

Astronomical Science
Hainaut, O., Meech, K. et al.
Rendezvous with `Oumuamua
ADS BibCode: 2018Msngr.173...13H
Hainaut, O., Meech, K., Micheli, M., Belton, M.
On 19 October 2017 the Panoramic Survey Telescope And Rapid Response System (Pan-STARRS) discovered a rapidly moving object near the Earth. In itself this was nothing unusual but over the course of a few days astronomers realised that this was the first detection of an unbound object travelling through the Solar System. At the time of its discovery, the interstellar visitor, 1I/2017 U1 (`Oumuamua), was quite faint and already speeding away. In the ensuing days, thanks to the efforts of about 10 separate teams, over 100 hours on 2.5- to 10-metre telescopes were devoted to observing the object during the short, exhilarating and frantic period over which it was visible. This is an account of our observations and how they have contributed to the current view that 1I/2017 U1 is an elongated object in an excited rotation state with surface colours similar to those of Solar System comets and asteroids.

Beccari, G., Petr-Gotzens, M. et al.
The Accretion Discs in Hα with OmegaCAM (ADHOC) Survey
ADS BibCode: 2018Msngr.173...17B
Beccari, G., Petr-Gotzens, M., Boffin, H., Jerabkova, T., Romaniello, M., Areal, M., Carraro, G., Celis, M., De Marchi, G., de Wit, W., Drew, J., Fedele, D., Ferrero, L., Kalari, V., Manara, C., Mardones, D., Martin, E., Meza, E., Mieske, S., Panagia, N., Testi, L., Vink, J., Walsh, J., Wright, N.
We present the first results of the Accretion Discs in Hα with OmegaCAM (ADHOC) survey, which aims to perform a deep and homogeneous photometric study of pre-main sequence (PMS) stars in a number of nearby star-forming regions. We took advantage of the exquisite image quality and wide-field capabilities of OmegaCAM at the VLT Survey Telescope (VST) to perform multi-band (ugri and Hα), deep (iSDSS < 22 mag), homogeneous and wide-field (covering tens of parsecs) observations of eight star-forming regions: the Orion Nebula Cluster, Lupus, Sco-Cen, Haffner 18, Vela OB2, Eta Cha, Chamaeleon and Ophiuchus. Using a robust method to identify PMS stars through their photometric excess in the Hα band, we aim to measure physical parameters (including mass accretion rates) for over 10 000 PMS stars. Direct comparison with low-resolution spectroscopy confirms that the objects with Hα excess emission that are detected photometrically are bona-fide PMS stars. The first results from this study clearly demonstrate the validity of the observational approach to unveiling complex stellar populations in young clusters.

Clark, S., Lohr, M. et al.
Life at the Extremes — Massive Star Formation and Evolution in the Galactic Centre
ADS BibCode: 2018Msngr.173...22C
Clark, S., Lohr, M., Najarro, F., Patrick, L., Evans, C., Dong, H., Figer, D., Lennon, D., Crowther, P.
Many galaxies host pronounced (circum)nuclear starbursts, fuelled by infalling gas. Such activity drives the secular evolution of the nucleus and may also generate super winds which enrich the interstellar and intergalactic medium. Given the intense radiation fields and extreme gas densities present within these nuclear regions, star formation may not occur in the same manner as it does in more “quiescent” regions of the galactic disc. To address this uncertainty, we are driven to investigate the only circumnuclear starburst where individual stars and star clusters may be resolved. Its proximity permitting dissection at resolutions a hundred times better than available for M31, the Galactic Centre provides us with a unique laboratory to study both stellar and galactic evolution.

Gadotti, D., Sánchez-Blázquez, P. et al.
Investigating the Formation and Evolution of Massive Disc Galaxies with the MUSE TIMER Project
ADS BibCode: 2018Msngr.173...28G
Gadotti, D., Sánchez-Blázquez, P., Falcón-Barroso, J., Husemann, B., Seidel, M., Leaman, R., Leung, G., van de Ven, G., Querejeta, M., Fragkoudi, F., de Lorenzo-Cáceres, A., Méndez-Abreu, J., Pérez, I., Kim, T., Martinez-Valpuesta, I., Coelho, P., Donohoe-Keyes, C., Martig, M., Neumann, J.
The Time Inference with MUSE in Extragalactic Rings (TIMER) project is a survey using the integral-field spectrograph Multi Unit Spectroscopic Explorer (MUSE) on the VLT to study 24 nearby barred galaxies with prominent central structures, such as nuclear rings or inner discs. One of our main goals is to estimate the cosmic epoch when galaxy discs settle, leading to the formation of bars. This is also the onset of a phase in the history of the Universe during which secular evolution processes in galaxies become important. We illustrate the quality of the data with some first results and describe the legacy potential of the survey.

Calistro Rivera, G., Hodge, J.
Resolving the Interstellar Medium at the Peak of Cosmic Star Formation
ADS BibCode: 2018Msngr.173...33R
Calistro Rivera, G., Hodge, J.
The interstellar medium feeds both the formation of stars and the growth of black holes, making it a key ingredient in the evolution of galaxies. With the advent of the Atacama Large Millimeter/submillimeter Array (ALMA), we can now probe the interstellar medium within high-redshift galaxies in increasingly exquisite detail. Our recent ALMA observations map the molecular gas and dust continuum emission in submillimetre-selected galaxies on 1–5 kpc scales, revealing significant differences in how the gas, dust continuum, and existing stellar emission are distributed within the galaxies. This study demonstrates the power of ALMA to shed new light on the structure and kinematics of the interstellar medium in the early Universe, suggesting that the interpretation of such observations is more complex than typically assumed.

Astronomical News
Bordelon, D., Grothkopf, U. et al.
The ESO Digital Object Identifier Service
ADS BibCode: 2018Msngr.173...38B
Bordelon, D., Grothkopf, U., Meakins, S.
Digital Object Identifiers (DOIs) are persistent identifiers in a global registry that assist in the citation, identification, and discoverability of research information. The ESO library has created a service to provide DOIs to departments within ESO. DOIs have been in use for articles in The Messenger since March 2017, and plans are underway to begin creating DOIs for datasets in the ESO Science Archive.

Lillo-Box, J., Opitom, C.
Report on the ESO Workshop "Diversis mundi: The Solar System in an Exoplanetary context (OPS-III)"
ADS BibCode: 2018Msngr.173...40L
Lillo-Box, J., Opitom, C.
Inspired by the previous two Observing Planetary Systems (OPS) workshops held in ESO-Chile and by the rapid evolution of exoplanet studies and Solar System exploration, we organised the Diversis Mundi workshop. The focus of this conference was to bring together the Solar System and exoplanet communities to put the Solar System into the context of the current knowledge of planetary systems and to understand all the known components of extrasolar systems. Around 100 researchers from both communities met and discussed these topics in a very collaborative and inspiring environment, and in a workshop format that enhanced the interaction between the two communities.

Biggs, A., Bridger, A. et al.
Report on the ESO Workshop "Proposal Submission Tools"
ADS BibCode: 2018Msngr.173...44B
Biggs, A., Bridger, A., Carpenter, J., De Breuck, C., Glendenning, B., Iono, D., Schmid, E., Testi, L.
The Atacama Large Millimeter/submillimeter Array (ALMA) Observing Tool is a desktop Java application which has been used very successfully since the beginning of science operations to submit requests for time during the annual Call for Proposals, as well as to prepare observing materials such as Scheduling Blocks. An ALMA upgrade study is currently looking at ways in which the OT might be modernised. As part of this study, a workshop was held at ESO Garching in order to bring together groups working on similar systems at observatories around the world.

Schipani, P., Arnaboldi, M. et al.
Report on the ESO–INAF Workshop "VST in the Era of the Large Sky Surveys"
ADS BibCode: 2018Msngr.173...46S
Schipani, P., Arnaboldi, M., Iodice, E., Leibundgut, B.
This workshop focussed on science programmes carried out with the INAF–ESO VLT Survey Telescope (VST) several years into its operation. The aim of the conference was to review the latest results and ongoing programmes, and to look ahead to future science cases, as well as potential synergies and collaborations with other projects and facilities.

Garcia, P., Filho, M. et al.
Report on the ESO–European Interferometry Initiative School "The 9th Very Large Telescope Interferometer School"
ADS BibCode: 2018Msngr.173...49G
Garcia, P., Filho, M., Amorim, A., Mérand, A.
The 9th Very Large Telescope Interferometer (VLTI) school guided participants through the process of acquiring and analysing VLTI observations from end to end, encompassing a range of steps, from scientific programme design to data reduction and exploration. This school was jointly funded by OPTICON (through the European Interferometry Initiative [EII]) and ESO. In total, 37 students participated and 15 lecturers were involved, ensuring broad coverage of topics. Continuous feedback was gathered throughout the school and the lecturers worked hard to fine-tune the programme using input from the students.

Arrigoni-Battaia, F., Löbling, L. et al.
The First ESO Astronomy Research Training — Ghana 2018
ADS BibCode: 2018Msngr.173...51A
Arrigoni-Battaia, F., Löbling, L., Man, A., Asabere, B., Kerzendorf, W., Valenti, E.
Designed by ESO astronomers, the Astronomy Research Training (ART) provides an intensive introductory course in astronomy to university-level students with no prior education in astronomy. The aim is to expand the astronomical community by empowering the participants to conduct research projects with open-source data. The first ESO ART was successfully conducted in Ghana in April 2018. We provide an overview of this new initiative here.

Dias, B., Zanella, A. et al.
Fellows at ESO
ADS BibCode: 2018Msngr.173...54E
Dias, B., Zanella, A., van der Burg, R.

Baade, D., Danziger, J. et al.
Leon B. Lucy, 1938–2018
ADS BibCode: 2018Msngr.173...58B
Baade, D., Danziger, J., Hook, R., Walsh, J.

Personnel Movements
ADS BibCode: 2018Msngr.173...59E