Tartu Observatory to survey tens of millions of southern sky objects with partners

The University of Tartu has signed a cooperation agreement with the consortium of the European Southern Observatory’s (ESO) future survey programme 4MOST, enabling the researchers of Tartu Observatory to participate in the programme. The goal of 4MOST is to survey tens of millions of objects in the southern sky within five years.

The agreement was signed as a result of Tartu Observatory’s Professor of Astronomy Elmo Tempel’s active work during the past three years. He joined the 4MOST programme in the autumn of 2016 when he started as a post-doctoral researcher at the Leibniz Institute for Astrophysics Potsdam, who are the leaders of the 4MOST consortium. Ever since then, the professor has actively participated in planning and developing the observation strategy of 4MOST.

Helps to explain one of the biggest mysteries in astrophysics

The 4MOST programme is named after its main instrument: the 4-metre Multi-Object Spectroscopic Telescope. During the programme, a state-of-the-art, high-multiplex, fibre-fed, optical spectroscopic survey facility will be constructed for ESO’s 4-metre VISTA telescope. 4MOST will enable to obtain spectra of 2436 objects at once. Due to the hexagonal field-of-view of four square degrees, most of the southern sky can be surveyed within five years.

The instrument helps to get valuable information about our home galaxy Milky Way’s chemical and dynamic composition. This is extremely important for understanding the formation of the Milky Way. Besides that, 4MOST enables to map a major part of the Universe seen in the southern sky while obtaining information about the evolution of galaxies. This is one of the most burning topics in modern astrophysics. The 4MOST programme also includes the observations of quasars and supernovas.

Tartu Observatory will help develop the survey strategy

The ground-based spectroscopic surveys are especially intended to complement the survey programmes of three European Space Agency’s space missions: Gaia, Euclid, and PLATO, as well as the European space mission eROSITA. If the 4MOST observations are combined with the ones made with the LSST and SKA telescopes that are being planned now, answers to questions that we haven’t even been able to ask yet could be found. The consortium’s close cooperation with present and future space as well as ground-based survey missions will make 4MOST one of the most important survey programmes of the following decades.

The survey programme is planned to start at the end of 2022 and last for five years. In the next few years, Tartu Observatory will mainly focus on working out the survey strategy and developing the software for survey selections.

In the future, 4MOST’s data will offer many research possibilities. Besides researching the Milky Way and the Universe, the data is of great significance for data scientists. The data collected with 4MOST will be much bigger than current data in total. This will offer an opportunity to develop and apply methods meant for big data processing.

More information can be found on the 4MOST webpage.

Additional information: Elmo Tempel, Professor of Astronomy at the University of Tartu Observatory, 737 4534, elmo.tempel@ut.ee