Astronomical News

Report on the ESO Workshop Rainbows on the Southern Sky: Science and Legacy Value of the ESO Public Surveys and Large Programmes held at ESO Headquarters, Garching, Germany, 5–9 October 2015

Magda Arnaboldi1 (VLT) and the New Technology Telescope extragalactic ; evolution; Marina Rejkuba1 (NTT), were added to the portfolio of the high-redshift and ; Bruno Leibundgut1 ­programmes enlarging the observational and the legacy value of Public­ Surveys Giacomo Beccari1 perspectives available to the community. and Large Programmes. Keynote speak- The Public Surveys lead to an increase ers provided an overview of the recent in the legacy value of from ESO tele- advances and open questions when intro- 1 ESO scopes on account of their homogeneity ducing their topic; the overviews were and uniformity for the sky area covered ­followed by invited talks from the Large and often include a time-domain com­ Programme and Public Survey principal This was the third ESO workshop on ponent. In 2010 and 2011, the nine imag- investigators (PIs) and by additional oral the science from Large Programmes ing Public Surveys started on VISTA and contributions. A concise summary of the and the second on Public Surveys. By the VST, and were soon followed by the content of the workshop is presented. design, this workshop covered all areas spectroscopic Public Surveys: PESSTO of research in , (Public ESO Spectroscopic Survey of providing a forum for the presentation Transient Objects) on the NTT; and Gaia- Legacy of Large Programmes and Public of the most recent scientific results ESO, LEGA-C (Large Early Galaxy Astro- Surveys from these programmes and fostering Census) and VANDELS (A deep discussions on the planned develop- VIMOS survey of the CANDELS Fields), all The workshop was opened by Bruno ments enabled by large and coherent on the VLT. The raw data from all Public Leibundgut, starting with a session on time allocations on ESO telescopes. Surveys are immediately public. In addi- the legacy value of Large Programmes Several aspects of the legacy value of tion, these programmes produce science and Public Surveys. The session focused such programmes – technological, data products, reduced images and spec- on the interplay between the research archival content, access to data, time tra, as well as catalogues of astrophysical topics in observational astronomy and domain and sociological — were evalu- measurements extracted from the science the feedback from the concept of the leg- ated and set a reference for future data. The science data products deliv- acy value of Large Programmes/Surveys. developments of ESO services to the ered by the Public Surveys, and pub- The legacy of an observing programme community. lished via the ESO Science Archive Facil- starts with the curation and archiving of ity (SAF), support new ways of conduct- its data and Alex Szalay covered these ing research and effectively enlarge the aspects in his keynote talk on the Sloan Introduction: Large Programmes and scientific community using ESO services. Digital Sky Survey (SDSS) projects. As Public Surveys at ESO the workshop progressed, it became ESO regularly organises workshops that clear that the legacy can provide a variety The ESO Large Programmes were intro- present an overview of the scientific of different metrics for the assessment of duced in 1996, following the recommen- advances enabled by the use of its facili- the success of these projects. Building dation of a working group nominated by ties and provide a forum for input by on well-known parameters, like the num- the Observing Programmes Committee the community on promising new pro- ber of publications and citations, other (OPC), with the aim of focusing on spe- jects and programmes. The assessment measures are the number of public cific science goals that require large time of the scientific return from the Large releases, training of young researchers, allocations, typically more than ten nights Programmes was the goal of two work- engagement of the wider population, as, (100 hours) and/or observations that shops in 2003 (Wagner & Leibundgut, for example, via the citizen science pro- span up to four observing periods. Since 2004) and in 2008 (Mathys & Leibundgut, jects such as the , enlarging then, about 13 % of the total available sci- 2009); the presentation of, and the first the network of scientific collaborations, ence time on ESO telescopes has been results from, the imaging Public Surveys as well as independent archive science allocated to Large Programmes and more were discussed in 2012 (Arnaboldi & and serendipitous discoveries that open than 150 such programmes have been Rejkuba, 2012). The first Large Pro- new fields. Alex Szalay made the point scheduled at the La Silla Paranal Obser- grammes workshop in 2004 included a that the way the science is done in vatory. A Large Programme is selected discussion with the community on sur- astronomy research is changing. Fast after a dedicated discussion that involves veys, which ultimately led to the estab- progress is now coming from multiwave- the whole OPC (in addition to the panels), lishment of ESO Public Surveys. The length and time-domain analysis of data, and these programmes are expected to 13 ongoing ESO Public Surveys and a thereby shifting the focus from smaller target scientific projects that are not pos- representative set of recently completed programmes driven by hypothesis to pro- sible within the regular time allocation Large Programmes were now the focus jects managing terabytes of data. Szalay and are relevant for a large fraction of the of the workshop referred to as the Rain- argued that the equivalent of “micro- astronomical community. bows2015 workshop1 and reported here. scopes” and “telescopes” for managing large volumes of data are the new instru- Since 2010, ESO Public Surveys, on the The workshop covered all areas of obser- ments that are needed. Visible and Infrared Survey Telescope for vational astronomy and the presentations Astronomy (VISTA), the VLT Survey Tele- were organised in seven sessions: planets; Guinevere Kauffmann elucidated very scope (VST), the Very Large Telescope stars; the Milky Way and Local Group; interesting points about some further

The Messenger 162 – December 2015 57 Astronomical News Arnaboldi M. et al., Report on the ESO Workshop “Rainbows on the Southern Sky”

changes in how research is being done and emphasised the need to coordinate efforts, transparency and the sharing of data and tools. The contributed talk by Sara Ellison further explored the use of neural networks for of the SDSS archive, while Marc Moniez emphasised the impact of the upcoming Large Synoptic Survey telescope.

Cosmology, galaxy evolution and extra- galactic astronomy

The first half of the workshop focused on cosmology, galaxy evolution and extraga- lactic astronomy. Three keynote speakers introduced the main areas: Richard Ellis (cosmology and the high-redshift Uni- verse), Natascha Foerster-Schreiber (gal- axy evolution) and Guinevere Kauffmann (extragalactic astronomy and the local Universe). These fields are rapidly devel- Figure 1. Participants of the Rainbows2015 work- oping thanks to the modern facilities, and shop in the entrance hall of ESO Headquarters. even more progress is anticipated from ongoing and future surveys. Many recent vations targeting the physics of ulation tracers in the Milky Way (Dante advances were enabled by ESO tele- (Ross McLure and Arjen van der Wel) and Minniti) and its satellites — the Magellanic scopes and featured in the invited talks cosmology. Clouds (Vincenzo Ripepi). The search for that covered, among other topics: the the most metal-poor stars in the halo search for high-redshift quasars (talk by (Piercarlo Bonifacio), the chemical enrich- Bram Venemans); the first objects that re- Dissecting galaxies into stars, planets ment of ultra-faint dwarf spheroidal gal- ionised the Universe (Laura Pentericci, and … black holes axies (Georges Kordopatis), and the Bo Milvang-Jensen); surveys of samples ­census of circumstellar discs in nearby of quasars which allow the intergalactic The Milky Way, the Local Group and the star-forming regions (Giacomo Beccari) and circumgalactic medium to be probed physics of stars and planets were covered were also covered. Mariya Lyubenova (talks by Trystyn Berg, Sebastian Lopez, during the central part of the workshop. presented a new stellar spectral library, Valentina D’Odorico and Tom Shanks); Hans-Walter Rix reviewed the composi- based on X-shooter observations. surveys of galaxies establishing galaxy tion and dynamics of the Milky Way disc growth, luminosity function evolution and around the Solar Neighbourhood and Reinhard Genzel presented the results star formation history across a range of to large radii. Maurizio Salaris described from the Galactic Centre Legacy Pro- redshifts (Storm Dunlop, Adriano Fontana, the recent advances and challenges in gramme. This is actually a series of many Rebecca Bowler and Lidia Tasca); and stellar : he pointed out that programmes that together comprise a cosmology constraints from the mapping specific details of the models have large long-term coherent monitoring experi- of the large-scale structure at z ~ 1 (Luigi uncertainties and their predictions can ment, which has unambiguously estab- Guzzo). Synergies with upcoming surveys, only be constrained by observations. The lished that there is a Schwarzschild–Kerr such as Euclid, were also mentioned. surveys of the Milky Way (Vista ­Variables black hole at the centre of the Milky Way, in the Via Láctea [VVV], the VST Photo- if general relativity is applicable. This At lower redshift and in the local Uni- metric Hα Survey [VPHAS+] and Gaia– ­programme continues to test the physical verse, results were presented on dark ESO) are providing large samples that processes in the vicinity of the Milky Way matter–baryon connections via gravita- enable star formation (Philipp Lucas), black hole and will enter a new phase in tional lensing (Alastair Edge, Hendrik stellar evolution and Galactic chemical the coming years when the star S2 will Hildebrandt and Piero Rosati), on the evolution (Rodolfo Smiljanic) to be again pass very close to the black hole, in ­kinematics of the outer halos of early- addressed, in addition to providing a first 2018. Several instruments will measure type galaxies (Claudia Pulsoni), and the complete view of the Milky Way Bulge this event, including the newest addition to diversity of dusty molecular tori in active (Dante Minniti, Manuela Zoccali, Chris the Paranal suite, aptly called GRAVITY. galactic nuclei (Klaus Meisenheimer). In Wegg and Matthieu Portail), and Disc general, the focus appears to be shifting (Sofia Randich, Boris Gaensicke). Variable The last session of the workshop covered from large-area redshift surveys towards stars were investigated as distance indi- time domain astrophysics, such as the need for high quality, deeper obser- cators (Wolfgang Gieren), as well as pop- supernovae (Stephen Smartt, Stefano

58 The Messenger 162 – December 2015 Benetti and Cosimo Inserra) as well as ESO Public Survey teams. Currently ­generated a vibrant atmosphere and led proper motion and parallaxes (Radostin archive papers contribute about 25 % to to ­vigorous discussions during lunches Kurtev), and ending with a review of the total number of refereed papers from and coffee breaks. The programme results on the characterisation and for- ESO facilities each year. was dense and diverse, with many excel- mation of planets. Didier Queloz gave an lent presentations. The talks from the exciting overview of the field, highlighting The support to the community is further ­Rainbow2015 workshops can be found how far we have come from the first dis- enhanced by the availability of science on the workshop page1. The photograph coveries of planets around other stars, data products from the science archives of the workshop participants is shown in to the physical characterisation of the at the Wide Field Astronomy Unit at the Figure 1. most extreme planetary systems. The Institute for Astronomy, University of High Accuracy Radial velocity Planet Edinburgh (Nicholas Cross) which pro- Several sociological aspects distinguished Searcher (HARPS) on the ESO 3.6-metre vides extensive programmatic access via this workshop from those in the past: is leading this field and has provided a SQL queries to their data assets. The – A number of Large Programme/Public census of the super-Earth and Neptune- requirements on survey project design Survey PIs could not attend the work- mass planet population around Solar- that must include not only new instru- shop and delegated the invited talks type stars (Francisco Pepe), while the VLT mentation, but also dedicated services to younger members of their teams. Interferometer provides exquisite resolu- for data processing, storage, effective Hence there was a healthy attendance tion to zoom into the early stages of publication and retrieval, was highlighted by young astronomers presenting the planet formation and protoplanetary disc in the case of the next generation spectro­ results from the large team efforts — physics (Jean-Philippe Berger). scopic surveys planned for the 4-Metre a new generation of European scien- Multi-Object Spectroscopic Telescope tists is clearly taking up a more promi- (4MOST; talk by Eduardo Gonzalez- nent role. Closing the loop: Legacy of Large Pro- Solares). – The selection of Large Programme grammes/Public Surveys and archives presentations invited by the Scientific Clearly the wealth of data available Organising Committee triggered some The closing session returned to data through Public Surveys and Large Pro- healthy responses from the Large Pro- archiving and access as one aspect of grammes transforms our view of the grammes community. In addition to the contribution to the legacy value of ­Universe into an N-dimensional space the inevitably limited selection of invited Large Programmes and Public Surveys. where correlations and information can talks, several other Large Programme The SAF is the collection point for Large be mined, and extracted to test and teams submitted requests for a con­ Programme and Public Survey products ­formulate new theories. On account of tributed talk and participated in the sci- and the primary point of publication/­ the web and fast-evolving archive tools, entific discussions. availability of these products to the ESO a large pool of users can now share – There was a strong representation of ­community as laid down by ESO Council the scientific method and join the astro- the Public Survey panels (Joint VISTA/ resolution #104 from 17–18 December nomical community. Diversity, openness, VST and the Spectroscopic panel) and 2004. Phase 3 — the process of prepara- ­curiosity and the unexpected are con- their members took part in the discus- tion, validation and ingestion of science cepts that can change our way of doing sions and interacted with the PIs of the data products for storage in the SAF, and astronomical research, and become Public Surveys. subsequent data publication to the scien- attributes of what is meant by “legacy – Surveys and Large Programmes tific community (Arnaboldi et al., 2014) — value”. empower the wider community to dis- ensures the coherent legacy and data cover the Universe. In this sense they return via the ESO SAF. are the effective implementation of the Concluding remarks IAU statement “The Universe: yours to Following the publication of the first data discover”. release from ESO Public Surveys in Scientific discoveries are driven by December 2011, the survey science data strongly motivated, highly interested products in the ESO SAF cover more ­individuals supported by leading-edge References than 11 500 square degrees (Optical/ technology developments. The com­ Arnaboldi, M. & Rejkuba, M. 2012, The Messenger, near-infrared: 4336 / 9445 square munity shares these discoveries and 150, 67 degrees) with more than 35 TB of data benefits via technology advances in Arnaboldi, M. et al. 2014, The Messenger, 156, 24 consisting of 2.7 × 105 files, with more archiving and data transfer. At the work- Mathys, G. & Leibundgut, B. 2009, The Messenger, than 2.6 × 106 spectra (Jörg Retzlaff). The shop we celebrated the achievements 135, 53 Wagner, S. & Leibundgut, B. 2004, The Messenger, data releases from ESO Public Surveys of the successful PIs and their teams 115, 41 include high-level science catalogues. who pursue important questions in on the data access and down- observational astrophysics with ESO load from the SAF were shown, including facilities. Links the cumulative number of archive users 1 Workshop programme: http://www.eso.org/sci/ of these products, amounting to twice The large variety of programmes and meetings/2015/Rainbows2015/program.html the number of PIs and Co-Is listed in the ­progress in different science fields

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