Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Astrophysicists from Clemson and Europe unmask a black hole

27.02.2012
A study of X-rays emitted a long time ago in a galaxy far, far away has unmasked a stellar mass black hole in Andromeda, a spiral galaxy about 2.6 million light-years from Earth.

Two Clemson University researchers joined an an international team of astronomers, including scientists at Germany's Max Planck Institute for Extraterrestrial Physics, in publishing their findings in a pair of scientific journals this week.

Scientists had suspected the black hole was possible since late 2009 when an X-ray satellite observatory operated by the Max Planck Institute detected an unusual X-ray transient light source in Andromeda.

"The brightness suggested that these X-rays belonged to the class of ultraluminous X-ray sources, or ULXs," said Amanpreet Kaur, a Clemson graduate student in physics and lead author of the paper published in the Astronomy & Astrophysics Journal. "But ULXs are rare. There are none at all in the Milky Way where Earth is located, and this is the first to be confirmed in Andromeda. Proving it required detailed observations."

Because ULX sources are rare — usually with just one or two in a galaxy, if they are present at all — there was very little data with which astronomers could make conjectures.

"There were two competing explanations for their high luminosities," said Clemson physics professor Dieter Hartmann, Kaur's mentor and a co-author of the paper. "Either a stellar mass black hole was accreting at extreme rates or there was a new subspecies of intermediate mass black holes accreting at lower rates. One of the greatest difficulties in attempting to find the right answer is the large distance to these objects, which makes detailed observations difficult or even impossible."

Working with scientists in Germany and Spain, the Clemson researchers studied data from the Chandra observatory and proved that the X-ray source was a stellar mass black hole that is swallowing material at very high rates.

Follow-up observations with the Swift and HST satellites yielded important complementary data, proving that it not only is the first ULX in Andromeda but also the closest ULX ever observed. Despite its great distance away, Andromeda is actually the nearest major galactic neighbor to our own Milky Way.

"We were very lucky that we caught the ULX early enough to see most of its light curve, which showed a very similar behavior to other X-ray sources from our own galaxy,” said Wolfgang Pietsch of the Max Planck Institute. The emission decayed exponentially with a characteristic timescale of about one month, which is a common property of stellar mass X-ray binaries. "This means that the ULX in Andromeda likely contains a normal, stellar black hole swallowing material at very high rates."

The emission of the ULX source, the scientists said, probably originates from a system similar to X-ray binaries in our own galaxy, but with matter accreting onto a black hole that is at least 13 times more massive than our Sun.

Unlike X-ray binaries in our own Milky Way, this source is much less obscured by interstellar gas and dust, allowing detailed investigations also at low X-ray energies.

Ideally, the astronomers would like to replicate their findings by re-observing the source in another outburst. However, if it is indeed similar to the X-ray binaries in our own Milky Way, they may be in for a long wait: Such outbursts can occur decades apart.

"On the other hand, as there are so many X-ray binaries in the Andromeda galaxy, another similar outbursting source could be captured any time by the ongoing monitoring campaign," Hartmann said. "While 'monitoring' may not sound exciting, the current results show that these programs are often blessed with discovery and lead to breakthroughs; in particular, if they are augmented with deep and sustained follow-up."

Dieter Hartmann | EurekAlert!
Further information:
http://www.clemson.edu

More articles from Physics and Astronomy:

nachricht JILA researchers make coldest quantum gas of molecules
22.02.2019 | National Institute of Standards and Technology (NIST)

nachricht (Re)solving the jet/cocoon riddle of a gravitational wave event
22.02.2019 | Max-Planck-Institut für Radioastronomie

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: (Re)solving the jet/cocoon riddle of a gravitational wave event

An international research team including astronomers from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has combined radio telescopes from five continents to prove the existence of a narrow stream of material, a so-called jet, emerging from the only gravitational wave event involving two neutron stars observed so far. With its high sensitivity and excellent performance, the 100-m radio telescope in Effelsberg played an important role in the observations.

In August 2017, two neutron stars were observed colliding, producing gravitational waves that were detected by the American LIGO and European Virgo detectors....

Im Focus: Light from a roll – hybrid OLED creates innovative and functional luminous surfaces

Up to now, OLEDs have been used exclusively as a novel lighting technology for use in luminaires and lamps. However, flexible organic technology can offer much more: as an active lighting surface, it can be combined with a wide variety of materials, not just to modify but to revolutionize the functionality and design of countless existing products. To exemplify this, the Fraunhofer FEP together with the company EMDE development of light GmbH will be presenting hybrid flexible OLEDs integrated into textile designs within the EU-funded project PI-SCALE for the first time at LOPEC (March 19-21, 2019 in Munich, Germany) as examples of some of the many possible applications.

The Fraunhofer FEP, a provider of research and development services in the field of organic electronics, has long been involved in the development of...

Im Focus: Regensburg physicists watch electron transfer in a single molecule

For the first time, an international team of scientists based in Regensburg, Germany, has recorded the orbitals of single molecules in different charge states in a novel type of microscopy. The research findings are published under the title “Mapping orbital changes upon electron transfer with tunneling microscopy on insulators” in the prestigious journal “Nature”.

The building blocks of matter surrounding us are atoms and molecules. The properties of that matter, however, are often not set by these building blocks...

Im Focus: University of Konstanz gains new insights into the recent development of the human immune system

Scientists at the University of Konstanz identify fierce competition between the human immune system and bacterial pathogens

Cell biologists from the University of Konstanz shed light on a recent evolutionary process in the human immune system and publish their findings in the...

Im Focus: Transformation through Light

Laser physicists have taken snapshots of carbon molecules C₆₀ showing how they transform in intense infrared light

When carbon molecules C₆₀ are exposed to an intense infrared light, they change their ball-like structure to a more elongated version. This has now been...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Global Legal Hackathon at HAW Hamburg

11.02.2019 | Event News

The world of quantum chemistry meets in Heidelberg

30.01.2019 | Event News

Our digital society in 2040

16.01.2019 | Event News

 
Latest News

JILA researchers make coldest quantum gas of molecules

22.02.2019 | Physics and Astronomy

Understanding high efficiency of deep ultraviolet LEDs

22.02.2019 | Materials Sciences

Russian scientists show changes in the erythrocyte nanostructure under stress

22.02.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>