Missing Black Hole Report: Hundreds Found!

Oct 25, 2007
Missing Black Holes Found
This image, taken with Spitzer´s infrared vision, shows a fraction of the black holes, which are located deep in the bellies of distant, massive galaxies (circled in blue). Credit: NASA/JPL-Caltech/Commissariat a l´Energie Atomique

Astronomers have unmasked hundreds of black holes hiding deep inside dusty galaxies billions of light-years away.

The massive, growing black holes, discovered by NASA's Spitzer and Chandra space telescopes, represent a large fraction of a long-sought missing population. Their discovery implies there were hundreds of millions of additional black holes growing in our young universe, more than doubling the total amount known at that distance.

"Active, supermassive black holes were everywhere in the early universe," said Mark Dickinson of the National Optical Astronomy Observatory in Tucson, Ariz. "We had seen the tip of the iceberg before in our search for these objects. Now, we can see the iceberg itself." Dickinson is a co-author of two new papers appearing in the Nov. 10 issue of the Astrophysical Journal. Emanuele Daddi of the Commissariat a l'Energie Atomique in France led the research.

The findings are also the first direct evidence that most, if not all, massive galaxies in the distant universe spent their youths building monstrous black holes at their cores.

For decades, a large population of active black holes has been considered missing. These highly energetic structures belong to a class of black holes called quasars. A quasar consists of a doughnut-shaped cloud of gas and dust that surrounds and feeds a budding supermassive black hole. As the gas and dust are devoured by the black hole, they heat up and shoot out X-rays. Those X-rays can be detected as a general glow in space, but often the quasars themselves can't be seen directly because dust and gas blocks them from our view.

"We knew from other studies from about 30 years ago that there must be more quasars in the universe, but we didn't know where to find them until now," said Daddi.

Daddi and his team initially set out to study 1,000 dusty, massive galaxies that are busy making stars and were thought to lack quasars. The galaxies are about the same mass as our own spiral Milky Way galaxy, but irregular in shape. At 9 to 11 billion light-years away, they existed at a time when the universe was in its adolescence, between 2.5 and 4.5 billion years old.

When the astronomers peered more closely at the galaxies with Spitzer's infrared eyes, they noticed that about 200 of the galaxies gave off an unusual amount of infrared light. X-ray data from Chandra, and a technique called "stacking," revealed the galaxies were, in fact, hiding plump quasars inside. The scientists now think that the quasars heat the dust in their surrounding doughnut clouds, releasing the excess infrared light.

"We found most of the population of hidden quasars in the early universe," said Daddi. Previously, only the rarest and most energetic of these hidden black holes had been seen at this early epoch.

The newfound quasars are helping answer fundamental questions about how massive galaxies evolve. For instance, astronomers have learned that most massive galaxies steadily build up their stars and black holes simultaneously until they get too big and their black holes suppress star formation.

The observations also suggest that collisions between galaxies might not play as large a role in galaxy evolution as previously believed. "Theorists thought that mergers between galaxies were required to initiate this quasar activity, but we now see that quasars can be active in unharassed galaxies," said co-author David Alexander of Durham University, United Kingdom.

"It's as if we were blindfolded studying the elephant before, and we weren't sure what kind of animal we had," added co-author David Elbaz of the Commissariat a l'Energie Atomique. "Now, we can see the elephant for the first time."

The new observations were made as part of the Great Observatories Origins Deep Survey, the most sensitive survey to date of the distant universe at multiple wavelengths.

Consistent results were recently obtained by Fabrizio Fiore of the Osservatorio Astronomico di Roma, Italy, and his team. Their results will appear in the Jan. 1, 2008, issue of Astrophysical Journal.

Source: NASA

Explore further: Cosmic puzzle settled: Comets give us shooting stars

add to favorites email to friend print save as pdf

Related Stories

The Wild West of physics

Jan 22, 2015

Call it macro-micro physics: the study of the huge paired with the study of the very, very small.

High-speed jets from a possible new class of galaxy

Jan 19, 2015

Seyfert galaxies are similar to spiral galaxies except that they have extraordinarily prominent, bright nuclei, sometimes as luminous as 100 billion Suns. Their huge energies are thought to be generated as ...

The cosmic seeds of black holes

Jan 19, 2015

Supermassive black holes with millions or billions of solar-masses of material are found at the nuclei of most galaxies. During the embryonic stages of these galaxies they are thought to play an important ...

Galactic 'hailstorm' in the early universe

Jan 16, 2015

Two teams of astronomers led by researchers at the University of Cambridge have looked back nearly 13 billion years, when the Universe was less than 10 percent its present age, to determine how quasars - ...

Will the real monster black hole please stand up?

Jan 08, 2015

(Phys.org)—A new high-energy X-ray image from NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR, has pinpointed the true monster of a galactic mashup. The image shows two colliding galaxies, collectively ...

Recommended for you

NOAA's DSCOVR going to a 'far out' orbit

4 hours ago

Many satellites that monitor the Earth orbit relatively close to the planet, while some satellites that monitor the sun orbit our star. DSCOVR will keep an eye on both, with a focus on the sun. To cover both ...

Cosmic puzzle settled: Comets give us shooting stars

8 hours ago

Suspicions that shooting stars come from comet dust, transformed into fiery streaks as they hit Earth's atmosphere, have been bolstered by Europe's Rosetta space mission, scientists reported Monday.

Mysteries in Nili Fossae

10 hours ago

These new images from the high-resolution stereo camera on ESA's Mars Express show Nili Fossae, one of the most enticing regions on Mars. This 'graben system' lies northeast of the volcanic region of Syrtis ...

User comments : 5

Adjust slider to filter visible comments by rank

Display comments: newest first

Ragtime
2 / 5 (5) Oct 25, 2007
The collisions between galaxies aren't important in quasar formation at all, because by aether theory the spherical dust galaxies are the product of quasars evaporation, instead. The frequency of quasars presence inside of distant galaxies excludes such model completelly, because the distant galaxies are very sparse.
Trippy
1 / 5 (2) Oct 25, 2007
Don't you ever get tired of being wrong Zephir?
fredrick
2.3 / 5 (3) Oct 25, 2007
yay zephir. personally I always look forward to your posts, those pictures are always awesome (and completely irrrelevent)
Trippy
3 / 5 (2) Oct 26, 2007
Personally they give me a headache, but as far as the article foes, it's pretty amazing (in my opinion anyway) because AFAIK, that was one of the problems that some people have with the BBT. Well, problem solved.

We've found them everywhere in the past, and we're finding them everywhere in the present.
fredrick
not rated yet Oct 26, 2007
I must say its odd that your comment just now got a such a low rating from the first voter Trippy (I just pushed it up with a 5)... It wasn't a bad comment, certainly not worse than a lot i've seen.

I'm noticing a lot of relatively good comments getting very mediocre scores, while the cranky and worthless (whingy "this isn't real science") comments quite often get higher.
Revenge comment rating by cranks?

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.