The latest edition of ESO's quarterly journal, The Messenger, is now available online. In issue 173 you will find information about Service Mode and Visitor Mode at Paranal, as well as new plans for proposal submission and selection. This issue also contains several articles presenting science highlights from ESO and ALMA facilities, news from ESO fellows and students, reports from workshops, and a tribute to Leon Lucy.

ESO, Garching, Germany, 6–8 May 2019

4MOST is a state-of-the-art, high-multiplex, optical spectroscopic survey facility currently under construction for ESO’s 4-metre VISTA telescope. During the first five years of operations 4MOST will be used to execute a comprehensive programme of both Galactic and extragalactic Public Surveys, and 30% of the observing time during this period will be available to the community. The process of selecting Community Public Surveys will be initiated by a Call for Letters of Intent for Public Spectroscopic Surveys, to be issued by ESO in mid-2019. In preparation of this Call, ESO and the 4MOST Consortium are jointly organising a workshop to prepare the ESO community for this exciting scientific opportunity, to assist potential PIs in successfully responding to the Call, and to foster scientific collaborations between the community and the 4MOST Consortium.

ESO, Garching, Germany, 17–21 June 2019  

The VLT provides a powerful suite of visible and infrared instruments, including unique capabilities like coherent and incoherent combinations of the four 8-metre Unit Telescopes and a multi-laser guided adaptive optics system.  In combination with ALMA, it represents comprehensive coverage across  the full parameter space encompassing ground-based observations in visible, infrared and sub-mm wavelengths. With the advent of ESO's Extremely Large Telescope (ELT) the VLT will take on a new role. It will still serve a large community and will continue to provide unique data. Its strengths will include a suite of versatile instrumentation on four 8-metre telescopes, the spatial resolution achievable by interferometry and a flexible operational model. The VLT, VLTI and the instrumentation have been maintained at peak performance and new capabilities have been developed.

A discussion of future science served by the VLT should be the basis for its development in the ELT era. The ELT, VLT in its many functions and the ESO 4-metre telescopes will form a powerful astrophysics resource. The new role of the VLT needs to be defined and this workshop will provide a discussion forum aimed at shaping the VLT's future.

La Serena, Chile, 25–29 March 2019

The La Silla Observatory was officially inaugurated on 25 March 1969. This event marked the culmination of the vision of European astronomers to create a major observatory in the Southern Hemisphere. In the following decades, La Silla served as the test-bed for developing technical and scientific expertise in the European astronomical community, establishing communications channels with the public at large and the interaction of an inter-governmental organisation and its host country, Chile. Relations with other astronomical facilities in the Andes mountains are also part of its history. La Silla has served as a superb site where national communities of ESO member states could install their experiments; some of these facilities regularly put the La Silla Observatory in the news. This conference celebrates the 50th anniversary of the inauguration of La Silla. We will review the significance of its history in all aspects and discuss possible future scenarios. The history of the Observatory including all of its many facets, and the research areas where La Silla telescopes have made important contributions will be reviewed.

The commissioning runs of MUSE in Narrow-Field Mode Adaptive Optics (NFM-AO) were carried out at the VLT on UT4 in April and June 2018. Several astronomical targets were observed to demonstrate the the capability of this new mode, find the best observing strategies and optimise the performance of the pipeline data reduction. The commissioning data have been released to illustrate the power of LTAO correction with MUSE NFM on different science targets; they can also be used as a reference to plan future programmes.

ESO’s Archive Science Portal provides an intuitive yet very powerful way of browsing, searching and downloading reduced science-ready data. Since the initial rollout three months ago, it has already been visited by more than approximately 1700 users (as inferred from the count of distinct IP addresses). Based on user feedback a new view mode has been implemented as a central new feature in addition to the already existing sky view (left-hand panel of figure above). It allows users to inspect, at a glance, the multi-dimensional query space in up to seventeen 1D distributions (right-hand panel of figure). They include physical parameters like sensitivity and signal-to-noise ratio, alongside more traditional ones such as Programme ID or instrumental setup. Users can easily interact with any list or histogram to add or remove search constraints and to build up rather complex queries in a progressive fashion.  

VANDELS  is a deep Public Spectroscopic Survey of high-redshift galaxies with the VIMOS spectrograph. It is designed to exploit the multi-wavelength imaging and near-infrared grism spectroscopy available in the CANDELS UDS and CDFS fields. The goal is to obtain spectra with sufficient signal-to-noise to derive metallicities and velocity offsets for absorption and emission lines independently, allowing a detailed investigation of the physics of galaxies in the early Universe. Within an area of 0.2 square degrees, the survey aims at delivering more than 2500 high signal-to-noise (~15-20) spectra of star-forming galaxies in the redshift range 2.5 < z < 5.5 and passive galaxies in the redshift range  1.5 < z < 2.5. This second data release (DR2) is based on observations carried out between August 2015 and August 2017 under the ESO Run IDs 194.A-2003(E-Q).

The Fizeau program in optical interferometry funds visits of researchers to institutes of their choice within the European Community to perform collaborative work and training on one of the active topics of the European Interferometry Initiative. The visits typically last for one month, and strengthen the network of astronomers engaged in technical, scientific and training work on optical/infrared interferometry. The programme is open for all levels of astronomers (from PhD students to tenured staff), with priority given to PhD students and young postdocs. Non-EU based missions will only be funded if considered essential by the Fizeau Committee. Applicants are also strongly encouraged to seek partial support from their home or host institutions.

ESO’s prestigious postdoctoral fellowship programme in both Garching (Germany) and Santiago (Chile) offers outstanding early-career scientists the opportunity to further develop their independent research programmes. From exoplanets to cosmology, observational, theoretical and fundamental astrophysics, these are all areas where ESO Fellows can benefit from a highly dynamic scientific environment, at some of the most advanced ground-based telescopes in the world. Do watch ESOCast 165 to hear what current ESO fellows have to say about the fellowship programme.

The Call for Proposals for observations at ESO telescopes in Period 103 (1 April 2019 – 30 September 2019) has been released. Please consult the Period 103 document for the main news items and policies related to applying for time on ESO telescopes. All technical information about the offered instruments and facilities is contained on ESO webpages that are linked from the Call. The proposal submission deadline is 12:00 CEST 27 September 2018.