News by Date
News by Category
Solar System
White Dwarfs
Neutron Stars
Black Holes
Milky Way Galaxy
Normal Galaxies
Galaxy Clusters
Cosmology/Deep Field
Press Resources
Status Reports
Press Advisories
Image Releases
Release Guidelines
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
Related Links

Chandra @ NASA
Visit the Chandra pages at the NASA portal (opens in new window)
Image Use
Image Use Policy & Request Form
Guidelines for utilizing images, applets, movies, and animations featured in this Web Site.
NASA's Chandra Finds Massive Black Holes Common in Early Universe

For Release: June 15, 2011


Correction: After this paper (Treister et al. 2011) was published and publicized a problem was discovered with the background subtraction used. Analysis by several groups, including the Treister et al. team, plus Willott (2011) and Cowie et al. (2012), shows that a significant detection of AGN (growing black holes) in the early universe can no longer be claimed.

Editor's Note: Honest errors such as this are part of the scientific process, especially on the frontiers of discovery. To quote Nobel laureate Frank Wilczek, "If you don't make mistakes, you're not working on hard enough problems. And that's a big mistake."


Cowie, L. et al. 2012, ApJ, in press

Treister, E. et al. 2011, Nature, 474, 356

Willott, C. 2011, ApJ, 742, L8

Chandra Deep Field South
Credit: X-ray: NASA/CXC/U.Hawaii/E.Treister et al; Infrared: NASA/STScI/UC Santa Cruz/G.Illingworth et al; Optical: NASA/STScI/S.Beckwith et al
Press Image and Caption

WASHINGTON -- Using the deepest X-ray image ever taken, astronomers found the first direct evidence that massive black holes were common in the early universe. This discovery from NASA's Chandra X-ray Observatory shows that very young black holes grew more aggressively than previously thought, in tandem with the growth of their host galaxies.

By pointing Chandra at a patch of sky for more than six weeks, astronomers obtained what is known as the Chandra Deep Field South (CDFS). When combined with very deep optical and infrared images from NASA's Hubble Space Telescope, the new Chandra data allowed astronomers to search for black holes in 200 distant galaxies, from when the universe was between about 800 million to 950 million years old.

Press Conference
From left are: Trent Perroto, NASA Public Affairs Officer; Wilt Sanders, Chandra Program Scientist at NASA Headquarters; Ezequiel Treister, astrophysicist, Institute for Astronomy at the University of Hawaii at Manoa; Kevin Schawinski, astrophysicist, Yale University; Priyamvada Natarajan, astrophysicist, Yale University and Mitch Begelman, Professor, Department of Astrophysical and Planetary Sciences, University of Colorado Boulder. Photo Credit: (NASA/Carla Cioffi)

"Until now, we had no idea what the black holes in these early galaxies were doing, or if they even existed," said Ezequiel Treister of the University of Hawaii, lead author of the study appearing in the June 16 issue of the journal Nature. "Now we know they are there, and they are growing like gangbusters."

The super-sized growth means that the black holes in the CDFS are less extreme versions of quasars -- very luminous, rare objects powered by material falling onto supermassive black holes. However, the sources in the CDFS are about a hundred times fainter and the black holes are about a thousand times less massive than the ones in quasars.

The observations found that between 30 and 100 percent of the distant galaxies contain growing supermassive black holes. Extrapolating these results from the small observed field to the full sky, there are at least 30 million supermassive black holes in the early universe. This is a factor of 10,000 larger than the estimated number of quasars in the early universe.

"It appears we've found a whole new population of baby black holes," said co-author Kevin Schawinski of Yale University. "We think these babies will grow by a factor of about a hundred or a thousand, eventually becoming like the giant black holes we see today almost 13 billion years later."

A population of young black holes in the early universe had been predicted, but not yet observed. Detailed calculations show that the total amount of black hole growth observed by this team is about a hundred times higher than recent estimates.

Because these black holes are nearly all enshrouded in thick clouds of gas and dust, optical telescopes frequently cannot detect them. However, the high energies of X-ray light can penetrate these veils, allowing the black holes inside to be studied.

Physicists studying black holes want to know more how the first supermassive black holes were formed and how they grow. Although evidence for parallel growth of black holes and galaxies has been established at closer distances, the new Chandra results show that this connection starts earlier than previously thought, perhaps right from the origin of both.

"Most astronomers think in the present-day universe, black holes and galaxies are somehow symbiotic in how they grow," said Priya Natarajan, a co-author from Yale University. "We have shown that this codependent relationship has existed from very early times."

It has been suggested that early black holes would play an important role in clearing away the cosmic "fog" of neutral, or uncharged, hydrogen that pervaded the early universe when temperatures cooled down after the Big Bang. However, the Chandra study shows that blankets of dust and gas stop ultraviolet radiation generated by the black holes from traveling outwards to perform this "reionization." Therefore, stars and not growing black holes are likely to have cleared this fog at cosmic dawn.

People Who Read This Also Read...

Chandra is capable of detecting extremely faint objects at vast distances, but these black holes are so obscured that relatively few photons can escape and hence they could not be individually detected. Instead, the team used a technique that relied on Chandra's ability to accurately determine the direction from which the X-rays came to add up all the X-ray counts near the positions of distant galaxies and find a statistically significant signal.

NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass.

More information, including images and other multimedia, can be found at: and

Media contacts:
Trent J. Perrotto
Headquarters, Washington

Janet Anderson
NASA Marshall Space Flight Center, Ala.

Megan Watzke
Chandra X-ray Center, Cambridge, Mass.

Visitor Comments (21)

Thanks for your question. Light can exist inside a black hole, it just cannot escape from beyond the event horizon.
-P. Edmonds, CXC

Posted by P. Edmonds on Friday, 11.9.12 @ 11:29am

Is there really light in a black hole?

Posted by Shock on Friday, 10.12.12 @ 12:02pm

The discovery of these BHs is a huge support for New Physics.!
According to the alternative standard model SM based Quantum FFF theory the Big bang is a splitting black hole process or splitting bunch of concentrated higgs particles leaving massive galaxy creating tandems of accelerated black holes behind, forming the Lyman alpha forest structure of the symmetrical entangled multi-universe


Posted by leo vuyk on Saturday, 06.2.12 @ 07:54am

Well, its not the universe expanding its the space between it.

Posted by austin virag on Sunday, 12.4.11 @ 17:44pm

On the picture I see 5 black holes just wondering if some day couple holes will be next to earth?

Posted by Joseph on Saturday, 08.27.11 @ 03:56am

Well if the early universe had so much black holes then expansion might have not happened at all due to force of gravity. The information which I believe will be more useful might to be find the number of black holes per square light year or something like that.

Posted by Shreyas Becker on Thursday, 06.23.11 @ 10:47am

Dear Ralph,
The assumption used here is that on large scales the Universe is uniform, if you look in one direction things are going to look similar to the way they look in any other direction. This assumption has been reinforced by decades of observations, so it is a perfectly reasonable one to make in this case (it's impossible to make these very deep observations across large sections of the sky). Also, it should be pointed out that the estimate of 30 million black holes in the early Universe is a conservative value, because it uses the lower limit on the number of growing black holes in the field. More importantly, there are likely to be many faint galaxies and black holes that are below the detection limits of our best telescopes.

Posted by P, Edmonds on Wednesday, 06.22.11 @ 10:33am

Thanks Marco for the compliments!
P. Edmonds, CXC

Posted by P. Edmonds on Wednesday, 06.22.11 @ 10:32am

Dear Ed,
These are all good questions. The stacked images take all the X-ray counts near the positions of the distant galaxies and add them up (this analysis was done separately for the low and high energy X-rays). So, just to make up some numbers you might have 4 counts from the source and 4 from the nearby background. This doesn't give a significant detection by itself, but if you add up hundreds of similar objects the counts from the sources will accumulate quickly, while the counts from the background will not accumulate so quickly because they're scattered around the sources in different positions (since they're noise).
For the scale of the image a redshift of 6.5 was assumed. The redshift was determined by HST observers using special photometric techniques used for very distant galaxies where spectroscopic redshifts are very difficult or impossible to obtain. A description is given here (q3):

It is the brightness of the X-ray emission and the large number of galaxies containing X-ray sources that implies the black holes are growing aggressively.

Posted by P. Edmonds on Wednesday, 06.22.11 @ 10:27am

Dear Andy,
The percentage of all material trapped in black holes continues to rise, although not as quickly as it did a few billion years ago and periods earlier than that. For example, there are several relatively nearby supermassive black holes that continue to grow at reasonably high rates, such as the object in Centaurus A. But, the number of growing black holes has decreased with time:
P. Edmonds, CXC

Posted by P. Edmonds on Wednesday, 06.22.11 @ 10:25am

Dear Marvin,
That's an interesting thought. There are certainly theories about why black holes come into existence, but I wouldn't say that black holes have a purpose any more than stars or galaxies have a purpose.
P. Edmonds, CXC

Posted by P. Edmonds on Wednesday, 06.22.11 @ 10:22am

Dear WebDev,
Thanks for your interesting ideas.
These observations detect objects in the early Universe, but not the *very* early Universe. It is generally believed that, not long after the Big Bang, the Universe entered a period called the Dark Ages before any star or black hole formed. This period is believed to have lasted about 100 million years.
P. Edmonds, CXC

Posted by P. Edmonds on Wednesday, 06.22.11 @ 10:20am

Dear Bill,
I like your analogy about black holes being like roach motels (and having lived in Sydney I'm very familiar with *big* roaches). Echoing another answer, it is generally believed that, not long after the Big Bang, the Universe entered a period called the "dark ages" before any star or black hole formed. So, these big black holes weren't around from the *very* beginning. Also, it must be remembered that although black holes have powerful gravity, they are not all-powerful. So, as a thought experiment, imagine the Sun turning into a black hole (which won't happen). The Earth would continue rotating around this black hole just like before and wouldn't be pulled in. Of course without radiation life on Earth wouldn't last very long!
P. Edmonds, CXC

Posted by P. Edmonds on Wednesday, 06.22.11 @ 10:17am

Seems like a bit of fanciful writing. First, the article claims astronomers have found "direct evidence that black holes are common in the early Universe", but later in the article we are told that, results imply "distant galaxies contain" black holes and that by, "extrapolating these results" to the full sky, there are calculated to be 30 million black holes in the early Universe.
That's what passes for direct evidence now. Sad.

Posted by Ralph on Monday, 06.20.11 @ 06:13am

As usual, something new to earn and most interesting. Are there any theories of what the purposes of Black Holes are?

Marvin L. S.

Posted by Marvin L. S . on Monday, 06.20.11 @ 01:20am

The first thing that came to my mind when I heard this news was:
- maybe what we call the edge of the universe is actually an infinite collection of black holes and
- maybe the big bang is actually a big fountain, forever streaming the raw materials that form galaxies and then black holes as they move away from the center.
Is anyone thinking along these lines?

Posted by WebDevDude on Sunday, 06.19.11 @ 20:44pm

Congratulations to the team for the discovery of Chandra, we are slowly uncovering the veil that separates us from the remotest times more towards the beginning of everything. Who knows if what they find will fulfill our expectations and our hopes of scientific men.
The definitive answer to the ultimate questions of infinity is getting closer and understandable. Thank you for your exciting research that arouse in us wonder and a sense of vertigo, and the truth will soon be a household name.
A greeting from Marco Avanzi Genoa, Italy

Posted by Marco Avanzi on Saturday, 06.18.11 @ 16:39pm

Please don't ask me to explain the laws of gravity, but it appears that a set percentage of all matter and energy generated in our early universe was trapped inside black holes and that no matter what size the universe grows to, the same set percentage of all matter and energy is still trapped inside black holes now. Maybe this is the constant that keeps the number and size of black holes in check.

Posted by Andy McDowall on Friday, 06.17.11 @ 06:02am

Oh my gosh, that's amazing and huge.

Posted by amani on Thursday, 06.16.11 @ 16:30pm

It is unclear what the "stacked" images show and how they were obtained. In stating that the image is 6.6 Myr across does one refer to the redshift 6-7 distance? and is it the size of the area at the time or today? How is the redshift determined Lyman 1216A H line? And how does one know that the holes are growing aggressively? For people with little expertise like myself, I feel the explanations are not quite adequate.

Posted by Ed Bond on Thursday, 06.16.11 @ 14:59pm

It makes me wonder what portion of all the normal matter that was created in the Big Bang has been trapped inside the holes? At least some stars recycle some stuff when they blow up. The Holes are like roach motels, the atoms go in, and never come out. Why didn't a big black hole eat up the entire early universe? Or did one almost succeed? And how did they interact with dark matter and energy, if they did at all. You have a few more thousand years of work to do.

Posted by Bill Simpson on Thursday, 06.16.11 @ 01:49am