Images by Date
Images by Category
Solar System
White Dwarfs
Neutron Stars
Black Holes
Milky Way Galaxy
Normal Galaxies
Galaxy Clusters
Cosmology/Deep Field
Images by Interest
Space Scoop for Kids
Sky Map
Photo Blog
Top Rated Images
Image Handouts
Fits Files
Image Tutorials
Photo Album Tutorial
False Color
Cosmic Distance
Look-Back Time
Scale & Distance
Angular Measurement
Images & Processing
Image Use Policy
Web Shortcuts
Chandra Blog
RSS Feed
Email Newsletter
News & Noteworthy
Image Use Policy
Questions & Answers
Glossary of Terms
Download Guide
Get Adobe Reader
H1821+643: NASA's Chandra Identifies an Underachieving Black Hole
Visual Description:

  • Astronomers have found a rapidly growing supermassive black hole (quasar) not achieving what they expect from it.

  • Quasars are rapidly growing supermassive black holes that pull material in at a very high rate.

  • H1821+643 is the closest quasar to Earth located in a galaxy cluster, at a distance of about 3.4 billion light-years.

  • Using NASA’s Chandra X-ray Observatory and the VLA, researchers found H1821+643 was less influential than many giant black holes in other clusters.

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.


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.


Fast Facts for H1821+643:
Credit  X-ray: NASA/CXC/Univ. of Nottingham/H. Russell et al.; Radio: NSF/NRAO/VLA; Image Processing: NASA/CXC/SAO/N. Wolk
Release Date  March 21, 2024
Scale  Image is about 1.1 arcmin (960,000 light-years) across.
Category  Black Holes, Groups & Clusters of Galaxies
Coordinates (J2000)  RA 18h 21m 57.40s | Dec +64° 20´ 37.0"
Constellation  Draco
Observation Dates  11 observations Oct 7, 2019 to Jul 15, 2020
Observation Time  93 hours 44 minutes (3 days 21 hours 44 minutes)
Obs. ID  22105-22108, 21558-21561, 23054, 23211, 23240
Instrument  ACIS
References Russell, H.R. et al., 2024, MNRAS, 528, 1863; arXiv:2401.03022.
Color Code  X-ray: blue; Radio: red
Distance Estimate  About 3.4 billion light-years (z=0.296)
distance arrow
Rate This Image

Rating: 4.0/5
(116 votes cast)
Download & Share

More Information
More Images
Chandra X-ray Image of H1821+643
Jpg, Tif
X-ray image

More Images
Animation & Video
A Tour of H1821+643

More Videos
More Releases
(14 Feb 19)

Related Images
(06 Nov 2023)
3C 297
3C 297
(08 Mar 2023)

Related Information
Related Podcast
Top Rated Images
Chandra Releases 3D Instagram Experiences

Brightest Cluster Galaxies

Timelapses: Crab Nebula and Cassiopeia A