Part of the Universe’s missing matter found thanks to the MUSE instrument

CRAL publication in MNRAS , on September 16, 2021. CNRS press release on September 16, 2021. Galaxies can receive and exchange matter with their external environment thanks to the galactic winds created by stellar explosions. Thanks to the MUSE instrument  from the Very Large Telescope at the ESO, an international research team, led on the French side by the CNRS and l'Université Claude Bernard Lyon 1 , has mapped a galactic wind for the first time. This unique observation, which is detailed in a study published in MNRAS on 16 September 2021, helped to reveal where some of the Universe's missing matter is located and to observe the formation of a nebula around a galaxy. Galaxies are like islands of stars in the Universe, and possess ordinary or baryonic matter, which consists of elements from the periodic table, as well as dark matter, whose composition remains unknown. One of the major problems in understanding the formation of galaxies is that approximately 80% of the baryons   that make up the normal matter of galaxies is missing.