"A tight-knit trio of ultrabright objects called quasars has been
discovered for the first time. Their proximity is probably not a
coincidence - violent interactions between their host galaxies may be
turning on the quasars by feeding the galaxies' colossal black holes
more matter than they can chew.

Quasars are very bright, compact objects in the distant universe. Each
is thought to be powered by matter heating up as it falls into a
supermassive black hole at the centre of a galaxy.

Of the 100,000 known quasars, only a few dozen are close enough
together to be considered binaries. Even so, that is still greater than
would be expected if the quasars were distributed randomly in the sky
(see Two for one).

Now, astronomers have found the first case of a triple quasar system,
an association that is even less likely to be due to chance. The trio
hints that galaxy interactions have triggered the quasar activity."

More at http://space.newscientist.com/article.ns?id=dn10915