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
RGG 118: Oxymoronic Black Hole Provides Clues to Growth
RGG 118

  • Astronomers have identified the smallest supermassive black hole found in the center of a galaxy.

  • The mass of the black hole is about 50,000 times that of the Sun, using data from the 6.5-meter Clay Telescope.

  • X-rays from hot gas swirling towards the black hole were detected by Chandra.

  • The black hole may help us understand the formation of much larger supermassive black holes.

Astronomers using NASA's Chandra X-ray Observatory and the 6.5-meter Clay Telescope in Chile have identified the smallest supermassive black hole ever detected in the center of a galaxy, as described in our latest press release. This oxymoronic object could provide clues to how much larger black holes formed along with their host galaxies 13 billion years or more in the past.

Astronomers estimate this supermassive black hole is about 50,000 times the mass of the Sun. This is less than half the previous lowest mass for a black hole at the center of a galaxy.

The tiny heavyweight black hole is located in the center of a dwarf disk galaxy, called RGG 118, about 340 million light years from Earth. Our graphic shows a Sloan Digital Sky Survey image of RGG 118 and the inset shows a Chandra image of the galaxy's center. The X-ray point source is produced by hot gas swirling around the black hole.

Researchers estimated the mass of the black hole by studying the motion of cool gas near the center of the galaxy using visible light data from the Clay Telescope. They used the Chandra data to figure out the brightness in X-rays of hot gas swirling toward the black hole. They found that the outward push of radiation pressure of this hot gas is about 1% of the black hole's inward pull of gravity, matching the properties of other supermassive black holes.

Accretion Disk

Artist's Illustration of Black Hole

Previously, a relationship has been noted between the mass of supermassive black holes and the range of velocities of stars in the center of their host galaxy. This relationship also holds for RGG 118 and its black hole.

The black hole in RGG 118 is nearly 100 times less massive than the supermassive black hole found in the center of the Milky Way. It is also about 200,000 times less massive than the heaviest black holes found in the centers of other galaxies.

Astronomers are trying to understand the formation of billion-solar-mass black holes that have been detected from less than a billion years after the Big Bang. The black hole in RGG 118 gives astronomers an opportunity to study a nearby small supermassive black hole in lieu of the first generation of black holes that are undetectable with current technology.

Astronomers think that supermassive black holes may form when a large cloud of gas, weighing about 10,000 to 100,000 times that of the Sun, collapses into a black hole. Many of these black hole seeds then merge to form much larger supermassive black holes. Alternately, a supermassive black hole seed could come from a giant star, about 100 times the Sun's mass, that ultimately forms into a black hole after it runs out of fuel and collapses.

Researchers will continue to look for other supermassive black holes that are comparable in size or even smaller than the one in RGG 118 to help choose between the two options mentioned above and refine their understanding of how these objects grow.

A preprint of these results is available online. The other co-author of the paper is Jenny Greene, from Princeton University in Princeton, New Jersey. NASA's Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra's science and flight operations.

Fast Facts for RGG 118:
Credit  X-ray: NASA/CXC/Univ of Michigan/V.F.Baldassare, et al; Optical: SDSS
Release Date  August 11, 2015
Scale  Image is 3.2 arcmin across (about 317,000 light years)
Category  Quasars & Active Galaxies
Coordinates (J2000)  RA 15h 23m 05.00s | Dec +11° 45´ 53.60"
Constellation  Serpens
Observation Date  26 Dec 2014
Observation Time  5 hours 30 min
Obs. ID  17538
Instrument  ACIS
References Baldassare, V.F. et al, 2015, ApJ (accepted); arXiv:1406.07531
Color Code  Inset X-ray (Pink); Optical: (Red, Green, Blue)
Distance Estimate  About 340 million light years
distance arrow
Visitor Comments (5)

A black hole should measure the sq root of the diameter of a galaxy. In a supernova explosion its size is reduced to the sq root of its original diameter. This gives a value of .001. This means that only .001 of the total mass of a galaxy is required to fuel the atomic energy required for reproduction. Take a galaxy of 200b stars will require 2b neutron stars in a black hole to re-produce a galaxy. If this is so we should find bumps in the background static every 200 years.

Posted by graham harris on Monday, 01.25.16 @ 16:56pm


Posted by lee michael brown on Wednesday, 10.7.15 @ 05:36am

This site was really helpful for my 9th grade science project. It really did have a lot of information. I will defiantly use this site in the future.

Posted by nathan hollar on Wednesday, 09.23.15 @ 11:35am

Super interesting, Congratulations.
Dr.Amalia KOkkinou

Posted by Dr.AMALIA KOKKINOU on Friday, 08.21.15 @ 06:08am

Awesome Literally, as our technology improves it's fascinating to observe the opinions theories of our scientists change to understand our universe.

Posted by ben on Tuesday, 08.11.15 @ 16:24pm

Rate This Image

Rating: 3.8/5
(668 votes cast)
Download & Share

More Information
More Images
X-ray Image of RGG 118
Jpg, Tif

More Images
Animation & Video
Tour of RGG 118

More Animations
Related Images
Henize 2-10
Henize 2-10
(10 Jan 11)

NGC 253
NGC 253
(05 Jun 01)

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

Brightest Cluster Galaxies

Timelapses: Crab Nebula and Cassiopeia A