Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Astronomers Catch Jet from Binge-Eating Black Hole

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:

More articles from Physics and Astronomy:

nachricht Light-driven atomic rotations excite magnetic waves
24.10.2016 | Max-Planck-Institut für Struktur und Dynamik der Materie

nachricht Move over, lasers: Scientists can now create holograms from neutrons, too
21.10.2016 | National Institute of Standards and Technology (NIST)

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: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Oasis of life in the ice-covered central Arctic

24.10.2016 | Earth Sciences

‘Farming’ bacteria to boost growth in the oceans

24.10.2016 | Life Sciences

Light-driven atomic rotations excite magnetic waves

24.10.2016 | Physics and Astronomy

More VideoLinks >>>