The Messenger

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Highlights include:

D’Odorico, S.: 40+ Years of Instrumentation for the La Silla Paranal Observatory
Mérand, A.: The VLTI Roadmap
Cirasuolo, M., Tamai, R. et al.: The ELT in 2017: The Year of the Primary Mirror
Bastian, T., Bárta, M. et al.: Exploring the Sun with ALMA

ADS BibCode: 2018Msngr.171....2D

As ESO Period 100 comes to a close, I look back at the development of ESO’s instrumentation programme over more than 40 years. Instrumentation and detector activities were initially started by a small group of designers, engineers, technicians and astronomers while ESO was still at CERN in Geneva in the late 1970s. They have since led to the development of a successful suite of optical and infrared instruments for the La Silla Paranal Observatory, as testified by the continuous growth in the number of proposals for observing time and in the publications based on data from ESO telescopes. The instrumentation programme evolved significantly with the VLT and most instruments were developed by national institutes in close cooperation with ESO. This policy was a cornerstone of the VLT programme from the beginning and a key to its success.

ADS BibCode: 2018Msngr.171....8H

Hainaut, O., Bierwirth, T., Brillant, S., Mieske, S., Patat, F., Rejkuba, M., Romaniello, M., Sterzik, M.

The Data Flow System is the infrastructure on which Very Large Telescope (VLT) observations are performed at the Observatory, before and after the observations themselves take place. Since its original conception in the late 1990s, it has evolved to accommodate new observing modes and new instruments on La Silla and Paranal. Several updates and upgrades are needed to overcome its obsolescence and to integrate requirements from the new instruments from the community and, of course, from ESO’s Extremely Large Telescope (ELT), which will be integrated into Paranal’s operations. We describe the end-to-end operations and the resulting roadmap guiding their further development.

ADS BibCode: 2018Msngr.171...14M

ESO’s Very Large Telescope Interferometer (VLTI) was a unique facility when it was conceived more than 30 years ago, and it remains competitive today in the field of milli-arcsecond angular resolution astronomy. Over the past decade, while the VLTI matured into an operationally efficient facility, it became limited by its first-generation instruments. As the second generation of VLTI instrumentation achieves first light, further developments for this unique facility are being planned and are described here.

ADS BibCode: 2018Msngr.171...20C

Cirasuolo, M., Tamai, R., Cayrel, M., Koehler, B., Biancat Marchet, F., González, J., Dimmler, M., Tuti, M., & the ELT team

The Extremely Large Telescope (ELT) is at the core of ESO’s vision to deliver the largest optical and infrared telescope in the world. With its unrivalled sensitivity and angular resolution the ELT will transform our view of the Universe: from exoplanets to resolved stellar populations, from galaxy evolution to cosmology and fundamental physics. This article focuses on one of the most challenging aspects of the entire programme, the 39-metre primary mirror (M1). 2017 was a particularly intense year for M1, the main highlight being the approval by ESO’s Council to proceed with construction of the entire mirror. In addition, several contracts have been placed to ensure that the giant primary mirror will be operational at first light.

ADS BibCode: 2018Msngr.171...25B

Bastian, T., Bárta, M., Brajša, R., Chen, B., Pontieu, B., Gary, D., Fleishman, G., Hales, A., Iwai, K., Hudson, H., Kim, S., Kobelski, A., Loukitcheva, M., Shimojo, M., Skokić, I., Wedemeyer, S., White, S., Yan, Y.

The Atacama Large Millimeter/submillimeter Array (ALMA) Observatory opens a new window onto the Universe. The ability to perform continuum imaging and spectroscopy of astrophysical phenomena at millimetre and submillimetre wavelengths with unprecedented sensitivity opens up new avenues for the study of cosmology and the evolution of galaxies, the formation of stars and planets, and astrochemistry. ALMA also allows fundamentally new observations to be made of objects much closer to home, including the Sun. The Sun has long served as a touchstone for our understanding of astrophysical processes, from the nature of stellar interiors, to magnetic dynamos, non-radiative heating, stellar mass loss, and energetic phenomena such as solar flares. ALMA offers new insights into all of these processes.

ADS BibCode: 2018Msngr.171...31C

Cami, J., Cox, N., Farhang, A., Smoker, J., Elyajouri, M., Lallement, R., Bacalla, X., Bhatt, N., Bron, E., Cordiner, M., de Koter, A., Ehrenfreund, P., Evans, C., Foing, B., Javadi, A., Joblin, C., Kaper, L., Khosroshahi, H., Laverick, M., Le Petit, F., Linnartz, H., Marshall, C., Monreal-Ibero, A., Mulas, G., Roueff, E., Royer, P., Salama, F., Sarre, P., Smith, K., Spaans, M., van Loon, J., Wade, G.

The ESO Diffuse Interstellar Band Large Exploration Survey (EDIBLES) is a Large Programme that is collecting high-signal-to-noise (S/N) spectra with UVES of a large sample of O and B-type stars covering a large spectral range. The goal of the programme is to extract a unique sample of high-quality interstellar spectra from these data, representing different physical and chemical environments, and to characterise these environments in great detail. An important component of interstellar spectra is the diffuse interstellar bands (DIBs), a set of hundreds of unidentified interstellar absorption lines. With the detailed line-of-sight information and the high-quality spectra, EDIBLES will derive strong constraints on the potential DIB carrier molecules. EDIBLES will thus guide the laboratory experiments necessary to identify these interstellar “mystery molecules”, and turn DIBs into powerful diagnostics of their environments in our Milky Way Galaxy and beyond. We present some preliminary results showing the unique capabilities of the EDIBLES programme.

ADS BibCode: 2018Msngr.171...37B

Baudry, A., Herpin, F., Humphreys, E., Torstensson, K., Vlemmings, W., Richards, A., Gray, M., De Breuck, C., Olberg, M.

We have used the Atacama Pathfinder Experiment (APEX) telescope with the sensitive Swedish-ESO PI APEX (SEPIA) Band 9 receiver to discover several new vibrationally excited line sources of water at 658 GHz in the atmosphere of selected O-rich evolved stars. We have shown that this transition is masing and can be used to probe the gas in the dust formation zone or the wind beyond the central star. The 658 GHz line is widespread in evolved stars but most sources are weaker than about 300–500 Jy. However, some exceptional cases reach up to a few thousand Jy. New models incorporating several vibrationally excited transitions of water allow us to predict the physical conditions prevailing in 658 GHz sources. The strongest ones could be mapped with ALMA to study the small-scale clumpiness of the gas in the dust formation zone or, more generally, the stellar wind.

ADS BibCode: 2018Msngr.171...43B

ADS BibCode: 2018Msngr.171...44R

ADS BibCode: 2018Msngr.171...46A

Andreani, P., Laing, R., Lu, H.

Polarised emission encodes essential physical information about many components of the Universe, ranging from dust grains and magnetic fields in molecular clouds, protoplanetary discs and evolved stars, through to the formation and propagation of relativistic outflows in Active Galactic Nuclei, and to the effects of inflation and primordial gravitational waves on Cosmic Microwave Background (CMB) anisotropies. The aim of this workshop was to bring together current and future ALMA users, observatory calibration experts and software developers from a broad range of research fields making use of polarimetric techniques in the frequency range between approximately 5 and 1000 GHz. This range was deliberately restricted in order to focus attention on common problems and to promote cross-fertilisation between different subject areas. The meeting provided an opportunity for the polarimetric community to develop collaborations, understand the latest technological developments and decide on common priorities for the future.

ADS BibCode: 2018Msngr.171...47E

Evans, C., Puech, M., Hammer, F., Gallego, J., Sánchez, A., García, L., Iglesias, J.

The Phase A design of MOSAIC, a powerful multi-object spectrograph intended for ESO’s Extremely Large Telescope, concluded in late 2017. With the design complete, a three-day workshop was held last October in Toledo to discuss the breakthrough spectroscopic surveys that MOSAIC can deliver across a broad range of contemporary astronomy.

ADS BibCode: 2018Msngr.171...49E

Kakkad, D., Bartlett, E., Lu, H.

ADS BibCode: 2018Msngr.171...52E

ADS BibCode: 2018Msngr.171...53E

The Messenger Issue 171