Credit X-ray: NASA/CXO/Ponticifca Catholic Univ. of Chile/F. Vito;
Radio: ALMA (ESO/NAOJ/NRAO); Optical: PanSTARRS
Data from NASA's Chandra X-ray Observatory have revealed what may be the most distant shrouded black hole, as reported in our press release. Found at a time only about 850 million years after the Big Bang, this black hole could help astronomers better understand an important epoch in the history of the Universe.
The large image shown here is from the optical PanSTARRS survey. The image on the left contains X-rays detected with Chandra from a small, central region (marked with a red cross) of the optical field. In the middle is the quasar
PSO167-13, which was first discovered with PanSTARRS. Optical
observations from these and other surveys have resulted in the detection
of about 200 quasars that, like PSO167-13, were already shining
brightly when the universe was less than a billion years old, or about 7
percent of its present age. On the right, the image shows the same
field of view as seen by the Atacama Large Millimeter Array (ALMA) of radio dishes in Chile. The bright source is the quasar and a faint, nearby companion galaxy is seen to the lower left.
Many black holes, especially in the early Universe, are expected to
be veiled by thick clouds of gas and dust. These are known as "obscured"
black holes. This cocoon of material makes it more difficult to find
and identify these black holes because it blocks much of the light that
is emitted from the region around the black hole.
Astronomers think that most of the early growth of black holes occurs while the black hole and disk
are strongly obscured. The cocoon of material feeds into the disk, and
as the black hole grows, the gas in the cloud is depleted until the
black hole and its bright disk are uncovered.
Optical light surveys are generally only considered effective at finding unobscured black holes, because the radiation
they detect is suppressed by even thin clouds of surrounding gas and
dust. Therefore, researchers expected that PSO167-13 would be
unobscured.
However, Chandra's unique ability to accurately record X-rays and
their positions showed the PSO167-13 was different. After 16 hours of
observation only three X-ray photons
were detected from PSO167-13, all with relatively high energies. Low
energy X-rays are more readily absorbed than higher energy ones, so the
likely explanation for the Chandra observation is that the quasar is
highly obscured by gas, allowing only high energy X-rays to be detected.
If confirmed, PSO167-13 beats the previous record-holder for an obscured quasar by approximately half a billion years.
A paper describing these results led by Fabio Vito of Pontificia
Universidad Católica de Chile was published today in Astronomy and
Astrophysics and is available online.
NASA's Marshall Space Flight Center manages the Chandra program. The
Smithsonian Astrophysical Observatory's Chandra X-ray Center controls
science and flight operations from Cambridge, Mass.
Fast Facts for QSO PSO167-13:
Scale: Large image is about 13.3 arcmin (14.5 million light years) across. Inset images are about 5 arcseconds (91,000 light years) across.
Category: Quasars & Active Galaxies, Black Holes
Coordinates (J2000): RA 11h 10m 33.98s | Dec -13° 29´ 45.6"
Constellation: Crater
Observation Date: Feb 20, 2018
Observation Time: 16 hours 33 minutes
Obs. ID: 20397
Instrument: ACIS
References: Vito F. et al., A&A Letters, published August 8, 2019; arXiv:1906.04241
Color Code: Large image (Optical: yellow and green); Inset images (X-ray: blue; Radio: red)
Distance Estimate: About 12.9 billion light years (z=6.515)
Source: NASA’s Chandra X-ray Observatory
