A group of scientists has mapped for the first time a galactic wind, depositing gas in a galaxyThus, he has discovered part of his command “Missing”.
Galaxies are seldom little islands of stars. Rather, dynamic structures, whose composition and evolution we are just beginning to discover, astrophysicist Nicolas Bouchet explained to the news agency. France Press agency.
According to current theories, Galaxies are formed above all by so-called dark matter, of unknown and invisible nature, and barely 16% of baryons, that is, atoms and molecules that we know about.
To make things more difficult, Current observations of the galaxy reveal only 20% of these baryons. The rest, the “lost” matter, is carried away by the galactic winds, a nebula of gas and dust caused by the explosion of stars within the galaxy.
An international team led by researchers from The Lyon Research Center for Astrophysics (Cral) has been able to map the nebula of that missing matter, using the music spectrometer of the VLT Large Telescope installed by the European Southern Observatory (ESO) in the Chilean Atacama Desert.
‘As if we saw an iceberg for the first time’Nicolas Bosch, a French researcher and co-author of the study published Thursday in the prestigious British Journal, explains MNRASWith Johannes Zabel from the Department of Astronomy at Saint Mary’s University of Canada.
Other researchers had located nebulae in galaxies, but they were more diffuse. this time The observation of Gal1, a fairly “young” galaxy, about 1,000 million years old, allowed the discovery of “a cloud of gas produced by that galactic wind, which escapes from both sides of the galactic disk, through two asymmetric cones”.
The dimensions of that cloud are enormous, in the order of more than 80,000 light-years from Gal1’s center. By comparison, our Milky Way galaxy is about 100,000 light-years in diameter.
This cloud is a kind of material deposit, equivalent to only “10 to 20% of the mass of the galaxy” FoundBouchet explained.
Part of the cloud pours back into the galactic disk to form those stars, some of which eventually explode, and They send matter back into the nebula, in a continuous circle.
Astronomers were lucky to have such A “beacon” to the quasar, a particularly luminous object in the universe, which made it possible to detect the presence of magnesium, an essential component of these nebulae, due to its proximity to the Gal1 galaxy.
(With information from AFP)