Quasar H1821+643.
X-ray: NASA/CXC/Univ. of Nottingham/H. Russell et al.;
Radio: NSF/NRAO/VLA; Image Processing: NASA/CXC/SAO/N. Wolk
This image shows a quasar, a rapidly growing supermassive black hole, which is not achieving what astronomers would expect
from it, as reported in our latest press release. Data from NASA’s
Chandra X-ray Observatory (blue) and radio data from the NSF’s Karl G. Jansky’s Very Large
Array (red) reveal some of the evidence for this quasar’s disappointing impact
on its host galaxy.
Known as H1821+643, this quasar is
about 3.4 billion light-years from Earth. Quasars are a rare and extreme class of supermassive
black holes that are furiously pulling material inwards, producing
intense radiation and sometimes powerful jets. H1821+643 is the closest quasar to Earth in a cluster of galaxies.
Quasars are different than other
supermassive black holes in the centers of galaxy clusters in that they are
pulling in more material at a higher rate. Astronomers have found that
non-quasar black holes growing at moderate rates influence their surroundings
by preventing the intergalactic hot gas from cooling down too much. This
regulates the growth of stars around the black hole.
The influence of quasars, however,
is not as well known. This new study of H1821+643 that quasars — despite being
so active — may be less important in driving the fate of their host galaxy and
cluster than some scientists might expect.
To reach this conclusion the team
used Chandra to study the hot gas that H1821+643 and its host galaxy are
shrouded in. The bright X-rays from the quasar, however, made it difficult to study the weaker
X-rays from the hot gas. The researchers carefully removed the X-ray glare to
reveal what the black hole’s influence is, which is reflected in the new
composite image showing X-rays from hot gas in the cluster surrounding the
quasar. This allowed them to see that the quasar is actually having little
effect on its surroundings.
Using Chandra, the team found that
the density of gas near the black hole in the center of the galaxy is much
higher, and the gas temperatures much lower, than in regions farther away.
Scientists expect the hot gas to behave like this when there is little or no
energy input (which would typically come from outbursts from a black hole) to
prevent the hot gas from cooling down and flowing towards the center of the
cluster.
A paper describing these results
has been accepted into the Monthly Notices of the Royal Astronomical Society
and is available online. The authors are Helen Russell (University of
Nottingham, UK), Paul Nulsen (Center for Astrophysics | Harvard & Smithsonian),
Andy Fabian (University of Cambridge, UK), Thomas Braben (University of
Nottingham), Niel Brandt (Penn State University), Lucy Clews (University of
Nottingham), Michael McDonald (Massachusetts Institute of Technology),
Christopher Reynolds (University of Maryland), Jeremy Saunders (Max Planck
Institute for Extraterrestrial Research), and Sylvain Veilleux (University of
Maryland).
NASA’s Marshall Space Flight Center
manages the Chandra program. The Smithsonian Astrophysical Observatory’s
Chandra X-ray Center controls science from Cambridge Massachusetts and flight
operations from Burlington, Massachusetts.
Read
more from NASA’s Chandra X-ray Observatory.
For more Chandra images, multimedia
and related materials, visit:
https://www.nasa.gov/mission/chandra-x-ray-observatory/
Visual Description:
This composite image shows a
quasar, a rare and extreme class of supermassive black hole, that’s located
about 3.4 billion light-years from Earth.
At the center of the image is a
bright, white, circular light, similar to the beam of a flashlight if it was
pointed directly toward you. A fuzzy, bar-shaped structure of red-colored radio
light, slightly larger than the width of the white light, surrounds the
circular structure. The red bar also extends above and below the white light,
stretching in a somewhat straight line from about the one o’clock position to
the seven o’clock position on a clock face.
On either side of the red bar, X-ray light is present as blue, wispy clouds of hot gas that are brighter closer to the red and white features. The brighter clouds represent more dense gas.
Source: NASA's Chandra Identifies an Underachieving Black Hole - NASA
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