Astronomers X-Ray Colliding Galaxies to Find a Pair of Monster Black Holes

When whole galaxies collide, it's a train wreck on a cosmic scale. Usually there's a near miss first, with each galaxy flying past the other. Both galaxies get distorted, their mutual gravity stretching them like taffy. They pull apart, but then their mutual gravity draws them together again, and the collision begins for real. What may have started as two lovely spiral or elliptical galaxies becomes chaos, the stars and gas clouds flung this way and that, and the resulting coalescing object a lu...