NASA’s Chandra X-ray Observatory has obtained definitive evidence that a
distant quasar formed less than a billion years after the Big Bang
contains a fully-grown supermassive black hole generating energy at the
rate of twenty trillion Suns. The existence of such massive black holes
at this early epoch of the Universe challenges theories of the formation
of galaxies and supermassive black holes.
Astronomers Daniel Schwartz and Shanil Virani of the Harvard-Smithsonian
Center for Astrophysics in Cambridge, MA observed the quasar, known as
SDSSp J1306, which is 12.7 billion light years away. Since the Universe
is estimated to be 13.7 billion years old, we see the quasar as it was a
billion years after the Big Bang. They found that the distribution of
X-rays with energy, or X-ray spectrum, is indistinguishable from that of
nearby, older quasars. Likewise, the relative brightness at optical and
X-ray wavelengths of SDSSp J1306 was similar to that of the nearby group
of quasars. Optical observations suggest that the mass of the black hole
is about a billion solar masses.
Evidence of another early-epoch supermassive black hole was published
previously by a team of scientists from the California Institute of
Technology and the United Kingdom using the XMM-Newton X-ray satellite.
They observed the quasar SDSSp J1030 at a distance of 12.8 billion light
years and found essentially the same result for the X-ray spectrum as
the Smithsonian scientists found for SDSSp J1306. Chandra’s precise
location and spectrum for SDSSp J1306 with nearly the same properties
eliminate any lingering uncertainty that precocious supermassive black
holes exist.
“These two results seem to indicate that the way supermassive black
holes produce X-rays has remained essentially the same from a very early
date in the Universe,” said Schwartz. “This implies that the central
black hole engine in a massive galaxy was formed very soon after the Big
Bang.”
There is general agreement among astronomers that X-radiation from the
vicinity of supermassive black holes is produced as gas is pulled toward
a black hole, and heated to temperatures ranging from millions to
billions of degrees. Most of the infalling gas is concentrated in a
rapidly rotating disk, the inner part of which has a hot atmosphere or
corona where temperatures can climb to billions of degrees.
Although the precise geometry and details of the X-ray production are
not known, observations of numerous quasars, or supermassive black
holes, have shown that many of them have very similar X-ray spectra,
especially at high X-ray energies. This suggests that the basic geometry
and mechanism are the same for these objects.
The remarkable similarity of the X-ray spectra of the young supermassive
black holes to those of much older ones means that the supermassive
black holes and their accretion disks, were already in place less than a
billion years after the Big Bang. One possibility is that millions of
100 solar mass black holes formed from the collapse of massive stars in
the young galaxy, and subsequently built up a billion-solar mass black
hole in the center of the galaxy through mergers and accretion of gas.
To answer the question of how and when supermassive black holes were
formed, astronomers plan to use the very deep Chandra exposures and
other surveys to identify and study quasars at even earlier ages.
The paper by Schwartz and Virani on SDSSp J1306 was published in the
November 1, 2004 issue of The Astrophysical Journal. The paper by Duncan
Farrah and colleagues on SDSS J1030 was published in the August 10, 2004
issue of The Astrophysical Journal.
Chandra observed J1306 with its Advanced CCD Imaging Spectrometer (ACIS)
instrument for approximately 33 hours in November 2003. NASA’s Marshall
Space Flight Center, Huntsville, Ala., manages the Chandra program for
NASA’s Office of Space Science, Washington. Northrop Grumman of Redondo
Beach, Calif., formerly TRW, Inc., was the prime development contractor
for the observatory. The Smithsonian Astrophysical Observatory controls
science and flight operations from the Chandra X-ray Center in
Cambridge, Mass.
Additional information and images are available at:
and
Science contacts:
Daniel Schwartz, dschwartz@cfa.harvard.edu, 617-495-7232
Shanil Virani, shanil.virani@yale.edu
