Sijie Yu, a physicist from UC Irvine, has recently published a study in the Monthly Notices of the Royal Astronomical Society. The review resumes on the work she and her scientific team has done in investigating Milky Way galaxy’s behavior.
It looks like when supernovas explode, their remains become the material from which other stars form. Sometimes, the outflows created by these explosions push content beyond the limit of the Milky Way and into its halo.
To understand this process, the team has used FIRE-2 simulations to recreate it. The footage looks like a real movie, at least for the uninitiated. Although, the specialists agree: “The FIRE-2 simulations allow us to generate movies that make it seem as though you’re observing a real galaxy,” said Sijie Yu.
The Milky Way galaxy ejects newborn stars
It might not make a lot of sense, so the uninitiated need some guidance to understand what they are looking at. They are the images of a supernova in the middle of the galaxy while it is forming a sort of a bubble by expelling gas. At the edge of this bubble, stars are building from the material ejected by the supernova. “It looks as though the stars are being kicked out from the center,” commented Yu.
There is something wonderful about this process – knowing that a dying star becomes the reason why new stars form. The gas is pushed beyond the limit of the galaxy in the circumgalactic space, where it is cooled and given a chance to aggregate into solid stars. It’s regeneration, is samsara, it’s like the Phenix myth. It rhymes somehow with the way life goes on here on Earth.
“Astronomers have long assumed that galaxies are assembled over lengthy periods as smaller star groupings come in and are dismembered by the larger body, a process that ejects some stars into distant orbits. But the UCI team is proposing ‘supernova feedback’ as a different source for as many as 40% of these outer-halo stars,” said James Bullock of UCI is a study co-author.
