Supernovas may eject gas, extending dwarfs but leaving them nearly starless
A. Di Cintio, C. Brook, NIHAO simulations and Hubble Space Telescope
Brilliant births and destructive deaths of stars might take a runt of a galaxy and stretch it to become a ghostly behemoth, new computer simulations show. This process could explain the origin of recently discovered dark galaxies, which can be as wide as the Milky Way but host roughly 1 percent as many stars.
Since 2015, astronomers have found hundreds of these shadowy systems lurking in and around several clusters of galaxies (SN: 12/10/16, p. 18). How these dark galaxies form is a puzzle. But prolific star formation and blast waves from exploding stars could be responsible, researchers suggest in a paper to appear in Monthly Notices of the Royal Astronomical Society Letters.
“The mystery is: Are these galaxies like the Milky Way, or are they dwarf galaxies?” says study coauthor Arianna