“This discovery dramatically changes our view on the origin of fast-moving stars,” said Monica Valluri, an astronomer at the University of Michigan. “The fact that the trajectory of this massive fast-moving star originates in the disk rather that at the Galactic center indicates that the very extreme environments needed to eject fast-moving stars can arise in places other than around supermassive black holes.”
In the nearby Whirlpool galaxy and its companion galaxy, M51b, two supermassive black holes heat up and devour surrounding material. These two monsters should be the most luminous X-ray sources in sight, but a new study using observations from NASA’s NuSTAR (Nuclear Spectroscopic Telescope Array) mission shows that a much smaller object is competing with the two behemoths.
Using quasars to measure the rate of the expansion of the universe has great potential, since we can observe them out to much greater distances from us than type-Ia supernovas to probe much earlier epochs in the history of the cosmos, says astronomer Elisabeta Lusso of Durham University.