The first 4MOST spectrograph ready to deliver

The first 4MOST spectrograph ready to deliver

Mon, 21/02/2022


The CRAL participates in the realization of spectrographs that will equip the next large telescopes to help us probe the Universe.

Among these, the two spectrographs of the european major project 4MOST will allow to analyze the light of several millions of stars and galaxies in the next years. Last December, the first of these two spectrographs (called Low-Resolution Spectrograph or LRS) successfully passed its "acceptance review". This is a key step during which the 4MOST project evaluates the performances and tests carried out and authorizes the transport of the spectrograph for its final integration in Potsdam, Germany.

Involving a team of 12 engineers, technicians and researchers from the Lyon Astrophysics Research Center (CRAL), the LRS is central to the 4MOST project, providing high-resolution spectral observations over a very wide band (from ultraviolet to infrared) and simultaneously on more than 800 astrophysical sources. These capabilities will make VISTA the largest telescope in the world dedicated to large astronomical surveys. Careful work has been done at the CRAL to perfectly align the complex optical systems that make up the LRS, and the goal will be to be able to maintain this performance after disassembly, delivery , reassembly and installation in Chile. Technical operations also continue at the CRAL with alignment and testing of the second 4MOST spectrograph, a sort of twin brother, which is scheduled for delivery to Germany in the fall. Both spectrographs will receive their first light on the Chilean telescope in 2023.

Photograph: view of the 4MOST spectrograph in the integration hall at the CRAL with a part of the team.

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