Astronomers have studied 51 quasars with NASA's Chandra X-ray Observatory and found they may represent an unusual population of black holes that consume excessive amounts of matter, as described in our latest press release. Quasars are objects that have supermassive black holes that also shine very brightly in different types of light.
By examining the X-ray properties with Chandra, and combining them with
data from ultraviolet and visible light observations, scientists are
trying to determine exactly how these large black holes grow so quickly
in the early Universe.
The quasars in this study - including the three shown as Chandra
images in the bottom of the graphic - are located between about 5
billion and 11.5 billion light years from Earth. These quasars were selected because they had unusually weak emission from certain atoms, especially carbon,
at ultraviolet wavelengths. Also, about 65% of the quasars in this new
study were found to be much fainter in X-rays, by about 40 times on
average, than typical quasars.
The weak ultraviolet atomic emission and X-ray fluxes from these
objects could be an important clue to the question of how a supermassive
black hole pulls in matter. Computer simulations show that, at low
inflow rates, matter swirls toward the black hole in a thin disk.
However, if the rate of inflow is high, the disk can puff up
dramatically into a torus or donut that surrounds the inner part of the
disk.
This is shown in the artist's illustration
in the top part of the main graphic. X-rays, produced in the white
region very near to the black hole, are substantially blocked by the
thick, donut-shaped part of the disk, making the quasar unusually faint
in X-rays. The X-rays are also prevented from striking the particles
that are being blown away from the outer parts of the disk in a wind.
This results in fainter ultraviolet emission from elements like carbon.
The important implication is that these "thick-disk" quasars may
harbor black holes growing at an extraordinarily rapid rate. The current
study and previous ones by different teams suggest that such quasars
might have been more common in the early Universe, only about a billion
years after the Big Bang. Such rapid growth might also explain the
existence of huge black holes at even earlier times.
A paper describing these results appears in an upcoming issue of The Astrophysical Journal and is available online.
The authors are Bin Luo (Penn State University), Niel Brandt (Penn
State), Patrick Hall (York University), Jianfeng Wu (Harvard-Smithsonian
Center for Astrophysics), Scott Anderson (University of Washington),
Gordon Garmire (Penn State), Robert Gibson (University of Washington),
Richard Plotkin (University of Michigan), Gordon Richards (Drexel
University), Don Schneider (Penn State), Ohad Shemmer (University of
North Texas), and Yue Shen (Carnegie Observatories).
NASA's Marshall Space Flight Center in Huntsville, Alabama, manages
the Chandra program for the agency's Science Mission Directorate in
Washington. The Smithsonian Astrophysical Observatory in Cambridge,
Massachusetts, controls Chandra's science and flight operations.
Fast Facts for 152156.48+520238.5:Scale: Image is 1 arcmin across. (1.64 million light years)
Category: Quasars & Active Galaxies
Coordinates (J2000): RA 15h 21m 56.50s | Dec +52° 02' 38.50"
Constellation: Boötes
Observation Dates: 22 Oct 2013
Observation Time: 10 hours 23 min
Obs. IDs: 15334
Instrument: ACIS
References: Luo, B. et al, 2015, ApJ (in press); arXiv:1503.02085
Color Code: Intensity
Distance Estimate: About 10.75 billion light years
Fast Facts for 153714.26+271611.6:
Scale: Image is 1 arcmin across. (1.62 million light years)
Category: Quasars & Active Galaxies
Coordinates (J2000): RA 15h 37m 14.30s | Dec +27° 16' 11.60"
Constellation: Corona Borealis
Observation Dates: 22 Dec 2013
Observation Time: 1 hours 40 min
Obs. IDs: 14955
Instrument: ACIS
References: Luo, B. et al, 2015, ApJ (in press); arXiv:1503.02085
Color Code: Intensity
Distance Estimate: About 11.03 billion light years
Fast Facts for 222256.11-094636.2:
Scale: Image is 1 arcmin across. (1.55 million light years)
Category: Quasars & Active Galaxies
Coordinates (J2000): RA 22h 22m 56.10s | Dec -09° 46' 36.20"
Constellation: Aquarius
Observation Dates: 27 Sep 2013
Observation Time: 2 hours 38 min
Obs. IDs: 14953
Instrument: ACIS
References: Luo, B. et al, 2015, ApJ (in press); arXiv:1503.02085
Color Code: Intensity
Distance Estimate: About 11.48 billion light years
Source: NASA’s Chandra X-ray Observatory
