Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

X-ray telescope finds new voracious black holes in early universe

16.06.2011
Using the deepest X-ray image ever taken, a University of Michigan astronomer and her colleagues have 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.


This is an artist's impression of a growing supermassive black hole located in the early universe, showing a disk of gas rotating around the central object that generates copious amounts of radiation. This gas is destined to be consumed by the black hole. Credit: NASA/CXC/A.Hobart

By pointing Chandra at a patch of sky for over 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 and 950 million years old.

"We had reason to expect that black holes existed in many of the very first galaxies, but they had evaded our searches until now. When I compared Chandra's data to my theoretical models I was stunned by their agreement. It's the dream of any theoretician," said Marta Volonteri, a U-M associate professor of astronomy and co-author of the study that appears in this week's Nature.

The super-sized growth means that the black holes in the CDFS are related to 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.

It was found that between 30 percent 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 baby 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.

"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. "Now we know they are there and they are growing like gangbusters."

Because these baby 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.

Two critical issues in black hole physics are 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 (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.

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 very 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.

The title of the Nature paper describing these results is "Black hole growth in the early Universe is self-regulated and largely hidden from view." The other co-author is Eric Gawiser from Rutgers University in New Jersey.

Jim Erickson | EurekAlert!
Further information:
http://www.umich.edu

More articles from Physics and Astronomy:

nachricht From rocks in Colorado, evidence of a 'chaotic solar system'
23.02.2017 | University of Wisconsin-Madison

nachricht Prediction: More gas-giants will be found orbiting Sun-like stars
22.02.2017 | Carnegie Institution for Science

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>