EIU Astro

EXTREME UNIVERSE: Early Quasar Is Brightest Object Ever Found in the Universe June 30, 2011

Artist concept of a nearby quasar, Image Credit: Gemini Observatory/AURA by Lynette Cook

It’s not the most distant object ever seen, but a redshift of 7.1, putting it at an age of 12.9 billion years old. It is the furthest quasar ever seen.  Seen in the picture below, the center red dot, it is also quite bright, it is estimated that it’s luminosity is 60 trillion times that of the sun!

What could power such a beast? In a paper published today in the journal Nature, it is estimated that a supermassive black hole of 2 billion solar masses would be necessary to power such a monster. I’ll also add, it must be well fed with gas and dust falling into it, as an isolated black hole would not be seen.

Image of the new most distant quasar ULAS J1120+0641. The quasar is the red dot near the center of the image. The picture is a color composite made from images taken with the Liverpool Telescope and the United Kingdom Infrared Telescope. The quasar lies in the constellation Leo, a few degrees from the bright galaxy Messier 66. Image Credit: UKIRT/Liverpool Telescope

Quasars like this were common in the universe one to ten billion years ago. Much earlier than ten billion years, it’s thought the universe would not have enough time to easily form black holes big enough to be seen as quasars.   ULAS J1120+0641 was formed only 770 million years after the big bang. It is estimated that only about 100 of these bright quasars are at this distance. It’s existence is an important clue into the formation of these supermassive black holes.

Although more distant objects have been confirmed (such as a gamma-ray burst at redshift 8.2, and a galaxy at redshift 8.6), the newly discovered quasar is hundreds of times brighter than these. Among objects bright enough to be studied in detail, this is the most distant by a large margin.

Its brightness, at 60 trillion times the luminosity of the sun, mean that even at this large distance you can get a quality spectrum.

The hunt for this object was a 5 year endeavor.The European UKIRT Infrared Deep Sky Survey (UKIDSS) which uses the UK’s dedicated infrared telescope in Hawaii was designed to solve this problem. The team of astronomers hunted through millions of objects in the UKIDSS database to find those that could be the long-sought distant quasars, and eventually struck gold.

“It took us five years to find this object,” explains Bram Venemans, one of the authors of the study. “We were looking for a quasar with redshift higher than 6.5. Finding one that is this far away, at a redshift higher than 7, was an exciting surprise. By peering deep into the reionisation era, this quasar provides a unique opportunity to explore a 100-million-year window in the history of the cosmos that was previously out of reach.”