A beginners guide to ESO

ESO is a large and complex organisation, which can be difficult to negotiate for a newcomer. It is relatively easy to find information about the available instrument suite, but can be more difficult to answer questions like: Which instruments are likely to be have the highest/lowest pressure factor (ESO’s word for oversubscription)? What new instruments are coming online, and on what timescale? How much time is taken up by guaranteed time observations (GTO) on my favourite instrument? Should I collaborate with a large program or GTO team? What new decisions are likely to be made that will affect my ability to use ESO? This post is intended to provide a summary of where to find answers to some of these questions.

ESO Management
ESO is run somewhat like a large company. The CEO is called the director general (DG), and is currently Xavier Barcons. Terms are 5 years, and often extended to two terms. The DG has a lot of freedom to make decisions about what ESO does, within the rules set by the board of directors, called the ESO Council. The Council represents the shareholders, who are the member states (plus Australia, as a Strategic Partner). Council documents are therefore very important, with key documents becoming public after each meeting. You can find them attached to the agenda of the most recent meeting, with historical meetings listed in a single page.

Like any CEO, Xavier delegates authority to his directors and sub-directors. Some of these key people in an Australian context are:

• Adrian Russell: Director of programmes, which essentially means new instruments.
• Luca Pasquini: Sub-director of the Paranal Instrumentation Program (PIP), which is most relevant to Australia.
• Andreas Käufer: Director of operations, and also sub-director of the La Silla/Paranal observatories.
• Rob Ivison: Director of science, which includes communication channels between ESO and scientists, as well as strategic decisions on science priorities and different kinds of observing programs.
• Bruno Leibundgut: Sub-director for VLT Science. And for a few Australians, Antoine Mérand is important for the VLTI.
• Ferdinando (Nando) Patat: Sub-director in charge of the Observing Programs Office (OPO), which includes the time allocation and scheduling process.

There are also other very important internal ESO people, such as Michèle Péron (director of engineering) and her sub-directors, although it is unlikely that Australian astronomers will deal with them directly.

ESO Committees
Although both Council and the ESO directors make decisions, they have advisory bodies to help them with expert external advice and to understand community opinion. The committee with the largest scope is arguably the Science and Technical Committee (STC), which is why it has to in turn be split into three subcommittees – the La Silla Paranal (LSP) subcommittee, the ELT subcommittee and ALMA committee, called the European Science Advisory Committee. The STC jointly advises Council and ESO Management on scientific and technical matters. Australia is entitled to one observer on the STC, although there are also members at large, and there are likely to be two Australians on both the STC and LSP in 2018 (subcommittee membership decisions to be made Feb 2018).

The best place to find STC outcomes is in the STC recommendations that become public after a council meeting. It is important to realise that conflict of interest provisions are taken seriously on these committees, which means that it is unlikely that an Australian will be drafting any recommendations that are particularly relevant to Australia’s instrument projects (given how national and interlinked our big projects are). However, this committee really does guide ESO strategy, and Australians should feel free to contact their STC member at any time.

The User Committee is most important in the process of appointing new members of the Observing Programmes Committee, and guiding astronomers interaction with ESO.

Past and Future Telescope Time Distribution
ESO releases a a variety of useful documents on pressure factors, number of proposals etc. Some, for example the update to Council (which includes national statistics), are regularly produced. Simple, easy to read summaries are periodically produced on the Science Announcements page, and you can receive them by email by ticking the box on your user portal page.

For future telescope time distribution and anticipated pressure factors for upcoming semesters, a lot of things have to be taken into account, including a careful reading of the call for proposals. Hopefully this is one place where this kind of collaborative space (AAL’s Australian ESO Forum) can come in handy!

Strategic Direction
The strategic direction of LSP is defined jointly by the directorates of science, programs and operations. The directorate of science publishes strategic papers from time to time, which affect both new instrumentation priorities, how public surveys came about, and when instruments are decommissioned. Instrument decommissioning is particularly important for the future of Paranal, because instruments are not swapped, and all ports on all telescopes (and the basement labs) are taken up. The more detailed plans of future instrumentation can be found in the 6-monthly PIP update. Looking at the PIP expenditure and FTEs in this plan, it is clear that although the future has a lower spend rate, there is room in principle for one moderate-sized instrument and a minor upgrade every 2 years. The balance between new instruments and upgrades/refurbishments will be difficult, and one where community input through the committees will be important.

GTO
On certain instruments, a large fraction of time can be taken up by Guaranteed Time Observations (GTO), which is a form of payment for the substantial labour it takes to build an ESO instrument. This has been one of the often discussed issues with Australia joining ESO, with opinions varying as to whether or not being part of large GTO programs is essential for fully engaging with ESO and maximising scientific outputs. At an estimated ~25% of available time over the next few coming periods (ESO-speak for semesters), which is temporarily higher than the long-term average.

ESO now publish the active GTO contracts, which represent most upcoming GTO.