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 When fluid flows almost as fast as light -- with quantum rotation
22.06.2018 | The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences

nachricht Thermal Radiation from Tiny Particles
22.06.2018 | Universität Greifswald

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: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Graphene assembled film shows higher thermal conductivity than graphite film

22.06.2018 | Materials Sciences

Fast rising bedrock below West Antarctica reveals an extremely fluid Earth mantle

22.06.2018 | Earth Sciences

Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View

22.06.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>