Merging galaxies create a binary quasar

Astronomers have found the first clear evidence of a binary quasar within a pair of actively merging galaxies. Binary quasars, like other quasars, are thought to be the product of galaxy mergers. Until now, however, binary quasars have not been seen in galaxies unambiguously in the act of merging. But images the Magellan telescope in Chile show two distinct galaxies with "tails" produced by their mutual gravitational attraction.[....]