Galaxy caught cannibalizing its neighbors

A team of astronomers has stared long and hard at a group of nearby galaxies to reveal how big galaxies grow by consuming their smaller neighbors. The team studied galaxies centered around one called M81, or Bode’s galaxy (pictured above), some 12 million light-years from Earth. Long exposures with Japan’s 8.2-meter Subaru T }elescope on Mauna Kea, Hawaii, and its ultrawide field camera—the Hyper Suprime-Cam—allowed them to see the faint outer regions of the galaxies, which are normally invisible. As they report online today inThe Astrophysical Journal Letters, the images showed streams of stars and other material being sucked into M81 from other galaxies by its stronger gravity. That gravity is also deforming the shapes of nearby galaxies and will likely consume them entirely with time. Astronomers have known for decades that galaxies, including our own Milky Way, grow large by consuming others, but this is the first time that evidence of such cannibalism has been so obviously on display, the researchers say. 

Posted in Space

{ http://sciencemag.org/ }