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Abell 644: How Often do Giant Black Holes Become Hyperactive?

  • A new study reveals how often some of the biggest black holes are active.

  • These results come from a massive survey of galaxies using data from the Chandra X-ray Observatory and the Sloan Digital Sky Survey.

  • The study has important implications for how a galaxy's environment affects the growth of the black hole at its center.

This two-panel graphic contains two composite images of galaxies used in a recent study of supermassive black holes. In each of the galaxies, data from NASA's Chandra X-ray Observatory are blue, and optical data from the Sloan Digital Sky survey are colored red, green and blue. The galaxy on the left, Abell 644, is in the center of a galaxy cluster that lies about 1.1 billion light years from Earth. On the right is an isolated, or "field," galaxy named XS04107B6_001, which is located about 900 million light years away. At the center of both of these galaxies is a growing supermassive black hole, called an active galactic nucleus (AGN) by astronomers, which is pulling in large quantities of gas.

A newly published study from Chandra tells scientists how often the biggest black holes in field galaxies like XS04107B6_001 have been active over the last few billion years. This has important implications for how environment affects black hole growth. The scientists found that only about one percent of field galaxies with masses similar to the Milky Way contain supermassive black holes in their most active phase. They also found that the most massive galaxies are the most likely to host these AGN, and that there is a gradual decline in the AGN fraction with cosmic time. Finally, the AGN fraction for field galaxies was found to be indistinguishable from that for galaxies in dense clusters, like Abell 644.

This study involves a survey called the Chandra Multiwavelength Project, or ChaMP, which covers 30 square degrees on the sky, the largest area covered of any Chandra survey to date. Combining Chandra's X-ray images with optical images from the Sloan Digital Sky Survey, about 100,000 galaxies were analyzed. Out of those, about 1,600 were bright in X-ray light, signaling possible AGN activity.

Fast Facts for Abell 644:
Credit  X-ray: NASA/CXC/Northwestern Univ/D.Haggard et al, Optical: SDSS
Release Date  December 20, 2010
Scale  Image is 13.2 arcmin on a side (3.53 million light years)13.2 arcmin
Category  Groups & Clusters of Galaxies Quasars & Active Galaxies
Coordinates (J2000)  RA 08h 17m 25.6s | Dec -7° 30´ 45"
Constellation  Hydra
Observation Date  3/26/2001
Observation Time  8 hours 20 min
Obs. ID  2211
Instrument  ACIS
References Haggard, D. et al, 2010 ApJ 723:1447-1468


Color Code  X-ray (Blue), Optical (Red, Yellow, White)
Distance Estimate  920 million light years (z=0.0701)
distance arrow
Fast Facts for SDSS J1021+1312:
Credit  X-ray: NASA/CXC/Northwestern Univ/D.Haggard et al, Optical: SDSS
Release Date  December 20, 2010
Scale  Image is 3.2 arcmin on a side (1.024 million light years)13.2 arcmin
Category  Normal Galaxies & Starburst Galaxies Quasars & Active Galaxies
Coordinates (J2000)  RA 10h 21m 47.86s | Dec +13° 12´ 28.19"
Constellation  Hydra
Observation Date  1/31/2003
Observation Time  2 hours 47 min
Obs. ID  4107
Instrument  ACIS
References Haggard, D. et al, 2010 ApJ 723:1447-1468


Color Code  X-ray (Blue), Optical (Red, Yellow, White)
Distance Estimate  1.1 billion light years (z=0.085)
distance arrow
Visitor Comments (10)

I understand elevated temperature enables particle detection by Chandra. Please explain how very hot gases can persist in the space. The same space just above our atmosphere is quite cold.

Posted by C A Young on Tuesday, 01.19.16 @ 18:56pm

Wow, that's amazing I didn't know that or even imagine that our Galaxy is embedded in an enormous halo of hot gas, that's so interesting, but can we get more information about the dark energy? because it represent I think more than the half of universe and it play an important role.

Posted by NASAFan on Saturday, 07.5.14 @ 08:42am

To Back who asked how the galaxy got so far away: The Big Bang theory as it presently exists is said to have included a period of "hyperinflation" of the (small--then suddenly large) universe very early in its history.

In addition, measurements made about a decade ago showed that even now the expansion of the universe is continuously accelerating.

Posted by Leonard on Wednesday, 08.22.12 @ 00:36am

Hi Bach,
Actually the age of the universe as I have read in many books is close to 14 billion years old.
Interesting question though and hope it gets answered by one of the Chandra team.
Marvin L. S.

Posted by Marvin L. S. on Tuesday, 01.11.11 @ 21:28pm

I have a simple question. With all the talk about the universe having started with a massive explosion and it being ONLY 12 Billion years old? can some please explain the following deduction.

Let's take this galaxy 1.1 LY away. Let's also assume the objects exploded at an average speed of 10M mph. In order for this galaxy to get that far away from us would take it 720B years. How then can the universe be only 12 B years old? Appreciate an explanation

Posted by Bach on Friday, 01.7.11 @ 12:59pm

The article shows the payoff from synergistic usage of two sets of instrumentation. Great work.

Posted by Chris on Thursday, 12.23.10 @ 01:55am

Thank you for the great shots, wow very interesting, will stay open for all information.

Posted by rick moll on Wednesday, 12.22.10 @ 02:54am

What is very interesting is the difference between a cluster galaxy and field galaxy but a middle supermassive black hole, it don't depend on the quantity and type of mater eated, what kind of star make a massive black hole, white dwarf, red magnestar, neutron star, this observation may show us that a super black hole isn't an evolution from a new black hole but depend of primaries state.

Posted by PECQUERY on Tuesday, 12.21.10 @ 21:21pm

Of utmost importance. If the AGN in our Milky Way is active, its radiation could destroy lifeformes on planets on a large scale. May be also on earth. This means destruction could be possible apart from destruction due to events in our planetary system and on earth.

Posted by H van Astenrode on Tuesday, 12.21.10 @ 10:57am

That is most interesting. So, has our galaxy been active like this in its past according to the above information?
There is so much to learn, how Astronomy and Astrophysics has grown over the past Century. A very complex subject.
Marvin L. S.

Posted by Marvin L. S. on Monday, 12.20.10 @ 21:04pm

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