Sunday, August 14, 2011

The Farthest Quasar

In the June 30 issue of NATURE, astronomers report discovery of the most distant quasar ever found. Once these enormously bright lights were called quasi stellar objects because scientists had no idea how distant or bright they really are. ULAS J1120+0641 dates from a time 12.9 billion years ago, about 770 million years after the Big Bang. This quasar emits 60 trillion times as much light as our Sun! It is powered by a Black Hole of 2 billion solar masses.

Dating from a time when few stars existed, this quasar is far too old to have formed from a collapsing star. It's central Black Hole must have formed from direct collapse shortly after the Big Bang. Size of a primordial Black Hole is related to the speed of light. Discovery of this massively powerful quasar is one more bit of evidence that c was much faster in the early Universe.