* Astronomy

Members Login
Post Info TOPIC: REJ1034+396


L

Posts: 131433
Date:
RE J1034+396
Permalink  
 


XMM-Newton has uncovered a well-tuned periodic signal from a super-massive black hole lodged at the centre of a galaxy, ending a long quest for such an object. The discovery provides scientists with a clearer picture on black hole accretion processes and an excellent tool to study active galactic nuclei (AGNs). These periodic signals originating from the black hole are emitted in X-rays, which are blocked out by the Earth's atmosphere - so the team used data from ESA's orbiting X-ray observatory, XMM-Newton, to make the discovery.

Read more 

__________________


L

Posts: 131433
Date:
RE: REJ1034+396
Permalink  
 


Title: A periodicity of approx1 hour in X-ray emission from the active galaxy RE J1034+396
Authors: Marek Gierlin acuteski, Matthew Middleton, Martin Ward & Chris Done

Active galactic nuclei and quasars are thought to be scaled-up versions of Galactic black hole binaries, powered by accretion onto supermassive black holes with masses of 10^610^9 solar masses as opposed to the ~ 10 solar masses in binaries . One example of the similarities between these two types of systems is the characteristic rapid X-ray variability seen from the accretion flow. The power spectrum of this variability in black hole binaries consists of a broad noise with multiple quasi-periodic oscillations superimposed on it. Although the broad noise component has been observed in many active galactic nuclei, there have hitherto been no significant detections of quasi-periodic oscillations. Here we report the discovery of an approx1-hour X-ray periodicity in a bright active galaxy, RE J1034+396. The signal is highly statistically significant (at the 5.6sigma level) and very coherent, with quality factor Q > 16. The X-ray modulation arises from the direct vicinity of the black hole.

Read more

__________________


L

Posts: 131433
Date:
Permalink  
 

Scientists at Durham University have found the "missing link" between small and super-massive black holes.
For the first time the researchers have discovered that a strong X-ray pulse is emitting from a giant black hole in a galaxy 500 million light years from Earth.
The pulse has been created by gas being sucked by gravity on to the black hole at the centre of the REJ1034+396 galaxy.
X-ray pulses are common among smaller black holes, but the Durham research is the first to identify this activity in a super-massive black hole. Most galaxies, including the Milky Way, are believed to contain super-massive black holes at their centres.
The researchers, who publish their findings in the prestigious scientific journal Nature today (Thursday, September 18), say their discovery will increase the understanding of how gas behaves before falling on to a black hole as it feeds and develops.
Astronomers have been studying black holes for decades and are able to "see" them due to the fact that gas gets extremely hot and emits X-rays before it is swallowed completely and is lost forever.
Using Europe's powerful X-ray satellite, XMM-Newton, they found that X-rays are being emitted as a regular signal from the super-massive black hole. The frequency of the pulse is related to the size of the black hole.

"Such signals are a well known feature of smaller black holes in our Galaxy when gas is pulled from a companion star. The really interesting thing is that we have now established a link between these light-weight black holes and those millions of times as heavy as our Sun. Scientists have been looking for such behaviour for the past 20 years and our discovery helps us begin to understand more about the activity around such black holes as they grow" - Dr Marek Gierlinski, in the Department of Physics, at Durham University.

Durham's scientists hope future research will tell them why some super-massive black holes show this behaviour while others do not.

Source: Durham University

__________________
Page 1 of 1  sorted by
Quick Reply

Please log in to post quick replies.



Create your own FREE Forum
Report Abuse
Powered by ActiveBoard