‘X’ marks the spot

[black holes meet]

When black holes meet: ‘When two galaxies collide, massive black holes in their respective centers fuse in a dramatic flourish that creates a telltale “X” mark, according to astronomers. Jets from the core of radio galaxy NGC326 …seem to have abruptly switched direction, a possible sign of a black hole merger.

The conclusion offers strong support to the theory that the gravitationally powerful black holes merge when galaxies crash into one another.’ CNN