SpaceGas halo flips galaxies from bright young things into has-beens Deep inside every galaxy is a tug of war between its forming stars and its voracious black hole, and its gas and mass that can make the difference 51¶¯Âþ
SpaceEinstein's clock: The doomed black hole to set your watch by Every 12 years, a black hole at the centre of a distant galaxy completes an orbit around an even bigger black hole, marking this with a violent outburst 51¶¯Âþ