Cosmic Whodunit: Gas Stripping May Be Killing Galaxies

Prior studies have looked at this mechanism in galaxies that reside in large groups known as galaxy clusters. Galaxies move when they are pulled on by the gravity of other, nearby galaxies or by dark matter, the mysterious material that is five times more common in the universe than "regular" matter. "During their lifetimes, galaxies can inhabit halos of different sizes, ranging from masses typical of [the halo around the Milky Way galaxy] to halos thousands of times more massive," Toby Brown, l