Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Astronomers Catch Jet from Binge-Eating Black Hole

13.12.2012
Back in January, a new X-ray source flared and rapidly brightened in the Andromeda galaxy (M31), located 2.5 million light-years away.

Classified as an ultraluminous X-ray source (ULX), the object is only the second ever seen in M31 and became the target of an intense observing campaign by orbiting X-ray telescopes -- including NASA's Swift -- and radio observatories on the ground. These efforts resulted in the first detection of radio-emitting jets from a stellar-mass black hole outside our own galaxy.


The ULX's radio-emitting jet (center) is unresolved in this image constructed from Very Long Baseline Array data. Each side of the image is 20 milliarcseconds across, or about the width of a human hair seen from a distance of half a mile. Credit: NRAO/M. Middleton et al.

A ULX is thought to be a binary system containing a black hole that is rapidly accreting gas from its stellar companion. However, to account for the brilliant high-energy output, gas must be flowing into the black hole at a rate very near a theoretical maximum, a feeding frenzy that astronomers do not yet fully understand.

"There are four black hole binaries within our own galaxy that have been observed accreting at these extreme rates," said Matthew Middleton, an astronomer at the Anton Pannekoek Astronomical Institute in Amsterdam. "Gas and dust in our own galaxy interfere with our ability to probe how matter flows into ULXs, so our best glimpse of these processes comes from sources located out of the plane of our galaxy, such as those in M31."

As gas spirals toward a black hole, it becomes compressed and heated, eventually reaching temperatures where it emits X-rays. As the rate of matter ingested by the black hole increases, so does the X-ray brightness of the gas. At some point, the X-ray emission becomes so intense that it pushes back on the inflowing gas, theoretically capping any further increase in the black hole's accretion rate. Astronomers refer to this as the Eddington limit, after Sir Arthur Eddington, the British astrophysicist who first recognized a similar cutoff to the maximum luminosity of a star.

"Black-hole binaries in our galaxy that show accretion at the Eddington limit also exhibit powerful radio-emitting jets that move near the speed of light," Middleton said. Although astronomers know little about the physical nature of these jets, detecting them at all would confirm that the ULX is accreting at the limit and identify it as a stellar mass black hole.

The European Space Agency's XMM-Newton observatory first detected the ULX, dubbed XMMU J004243.6+412519 after its astronomical coordinates, on Jan. 15. Middleton and a large international team then began monitoring it at X-ray energies using XMM-Newton and NASA's Swift satellite and Chandra X-ray Observatory. The scientists conducted radio observations using the Karl G. Jansky Very Large Array (VLA) and the continent-spanning Very Long Baseline Array, both operated by the National Science Foundation in Socorro, N.M., and the Arcminute Microkelvin Imager Large Array located at the Mullard Radio Astronomy Observatory near Cambridge, England.

In a paper published online by the journal Nature on Wednesday, Dec. 12, the scientists reveal their successful detection of intense radio emission associated with a jet moving at more than 85 percent the speed of light. VLA data reveal that the radio emission was quite variable, in one instance decreasing by a factor of two in just half an hour.

"This tells us that the region producing radio waves is extremely small in size -- no farther across than the distance between Jupiter and the sun," explained team member James Miller-Jones, a research fellow at the Curtin University node of the International Centre for Radio Astronomy Research in Perth, Western Australia.

Black holes have been conclusively detected in two varieties: "lightweight" ones created by stars and containing up to a few dozen times the sun's mass, and supermassive "heavyweights" of millions to billions of solar masses found at the centers of most big galaxies. Astronomers have debated whether many ULXs represent hard-to-find "middleweight" versions, containing hundreds to thousands of solar masses.

"The discovery of jets tells us that this particular ULX is a typical stellar remnant about 10 times the mass of the sun, swallowing as much material as it possibly can," Middleton said. "We may well find jets in ULXs with similar X-ray properties in other nearby galaxies, which will help us better understand the nature of these incredible outflows."

Commenting on the findings on behalf of the Swift team, Stefan Immler at NASA's Goddard Space Flight Center in Greenbelt, Md., noted that it was almost exciting enough for astronomers to witness a new ULX so close to home, even if "close" is a few million light-years away. "But detecting the jets is a real triumph, one that will allow us to study the accretion process of these elusive black hole candidates in never-before-seen detail," he said.

Francis Reddy
NASA's Goddard Space Flight Center, Greenbelt, Md.

Francis Reddy | EurekAlert!
Further information:
http://www.nasa.gov
http://www.nasa.gov/topics/universe/features/andromeda-xray.html

More articles from Physics and Astronomy:

nachricht Astronomers find unexpected, dust-obscured star formation in distant galaxy
24.03.2017 | University of Massachusetts at Amherst

nachricht Gravitational wave kicks monster black hole out of galactic core
24.03.2017 | NASA/Goddard Space Flight Center

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: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Northern oceans pumped CO2 into the atmosphere

27.03.2017 | Earth Sciences

Fingerprint' technique spots frog populations at risk from pollution

27.03.2017 | Life Sciences

Big data approach to predict protein structure

27.03.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>