This is an artist's rendering of a very
distant, very ancient quasar
Courtesy of the European Southern Observatory (M. Kornmesser)
Courtesy of the European Southern Observatory (M. Kornmesser)
Washington, D.C.— Quasars--supermassive black holes
found at the center of distant massive galaxies--are the most-luminous
beacons in the sky. These central supermassive black holes actively
accrete the surrounding materials and release a huge amount of their
gravitational energy. An international team of astronomers, including
Carnegie’s Yuri Beletsky, has discovered the brightest quasar ever found
in the early universe, which is powered by the most massive black hole
observed for an object from that time. Their work is published February
26 by Nature.
The quasar was found at a redshift of z=6.30. This is a measurement of
how much the wavelength of light emitted from it that reaches us on
Earth is stretched by the expansion of the universe. As such, it can be
used to calculate the quasar’s age and distance from our planet. A
higher redshift means larger distance and hence looking further back in
time.
At a distance of 12.8 billion light years from Earth, this quasar was
formed only 900 million years after the Big Bang. Named SDSS J0100+2802,
studying this quasar will help scientists understand how quasars
evolved in the earliest days of the universe. There are only 40 known
quasars have a redshift of higher than 6, a point that marks the
beginning of the early universe.
“This quasar is very unique. Just like the brightest lighthouse in the
distant universe, its glowing light will help us to probe more about the
early universe,” said team-leader Xue-Bing Wu of Peking University and
the Kavli Institute of Astronomy and Astrophysics.
With a luminosity of 420 trillion that of our own Sun’s, this new
quasar is seven times brighter than the most distant quasar known (which
is 13 billion years away). It harbors a black hole with mass of 12
billion solar masses, proving it to be the most luminous quasar with the
most massive black hole among all the known high redshift quasars.
The team developed a method of detecting quasars at redshifts of 5 and
higher. These detections were verified by the 6.5-meter Multiple Mirror
Telescope (MMT) and 8.4m Large Binocular Telescope (LBT) in Arizona; the
6.5m Magellan Telescope at Carnegie’s Las Campanas Observatory in
Chile; and the 8.2m Gemini North Telescope in Hawaii.
“This quasar is a unique laboratory to study the way that a quasar’s
black hole and host galaxy co-evolve,” Beletsky said. “Our findings
indicate that in the early Universe, quasar black holes probably grew
faster than their host galaxies, although more research is needed to
confirm this idea.”
Other co-authors on the paper are: FeigeWang, Jinyi Yang, and Qian
Yang, also of Peking University and the Kavli Institute; Xiaohui Fan of
University of Arizona and the Kavli Institute; Weimin Yi of the Chinese
Academy of Sciences; Wenwen Zuo of Peking University and the Chinese
Academy of Sciences; Fuyan Bian of Australian National University;
Linhua Jiang and RanWang of the Kavli Institute; and Ian D. McGreer and
David Thompson of University of Arizona.
This work was funded by the NSFC, the Strategic Priority Research
Program ”The Emergence of Cosmological Structures” of the Chinese
Academy of Sciences, the National Key Basic Research Program of China,
and the U.S. NSF.
