June 29, 2011
Scientists Discover Most Distant Quasar Known To Exist
Scientists said on Wednesday that they have discovered the most distant quasar to date, thriving at a time when the Universe was less than 800 million years old.
The object is around 100 million years younger than the previously known most distant quasar.
Prior to its discovery, the most distant quasar was about 870 million years old. The scientists said the newly discovered object was around when the Universe was about 770 million years old, which is only five percent of its current age.
Dr. Simon Dye of the University of Nottingham said in a statement: "Objects that lie at such large distance are almost impossible to find in visible-light surveys because their light is stretched by the expansion of the universe. This means that by the time their light gets to Earth, most of it ends up in the infrared part of the electromagnetic spectrum."
"It took us five years to find this object. We were looking for a quasar with a redshift higher than 6.5. Finding one this far away, at a redshift higher than 7, was an exciting surprise. This quasar provides a unique opportunity to explore a 100 million year window of the cosmos that was previously out of reach."
Quasars are very bright and distant galaxies that are believed to be powered by supermassive black holes at their centers.
The astronomers found the record-holding quasar using the U.K. Infra-Red Telescope (UKIRT) in Hawaii. The distance to the quasar was confirmed by observations made with the FORS2 instrument on the European Southern Observatory Very Large Telescope (VLT) and instruments on the Gemini North Telescope.
The scientists said the existence of such a massive black hole so early on in the history of the University means that current models for the growth of these objects may need to be revised.
The findings are published in the June 30, 2011 edition of the journal Nature.
Image Caption: This artist's impression shows how ULAS J1120+0641, a very distant quasar powered by a black hole with a mass two billion times that of the Sun, may have looked. This quasar is the most distant yet found and is seen as it was just 770 million years after the Big Bang. This object is by far the brightest object yet discovered in the early Universe. Credit: ESO/M. Kornmesser
On the Net: