Leicester: New class of black hole

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Leicester: New class of black hole

Post by bystander » Thu Sep 09, 2010 1:26 am

Extreme X-ray source supports new class of black hole
University of Leicester | via EurekAlert | 08 Sept 2010
Team led by University of Leicester confirm presence of ultra-bright object in nearby galaxy

A group of international astronomers in the UK, France and the USA, led by the University of Leicester, have found proof to confirm the distance and brightness of the most extreme ultra-luminous X-ray source, which may herald a new type of Black Hole.

The X-ray source, HLX-1, is the most extreme member of an extraordinary class of objects – the ultra-luminous X-ray sources – and is located in the galaxy ESO 243-49 at a distance of ~300 million light years from the Earth.

The astronomers' findings confirm that the extreme luminosity (which is a factor of ~100 above most other objects in its class, and a factor of ~10 higher than the next brightest ultra-luminous X-ray source) is correct.

This is forcing scientists to rethink their theories on the maximum brightness of ultra-luminous X-ray sources, and provides support to the idea that HLX-1 may contain an intermediate mass black hole.

This latest result will be reported today (8 September) in the scientific journal, 'The Astrophysical Journal'.

Using the European Southern Observatory's (ESO's) Very Large Telescope (VLT) in Chile, the team have obtained an optical spectrum of their record breaking ultra-luminous X-ray source (HLX-1) in the distant galaxy ESO 243-49.

Their findings enable them to show conclusively that HLX-1 is indeed located within this galaxy, and is neither a foreground star nor a background galaxy. The main implication of this discovery is that ultra-luminous X-ray sources such as HLX-1 can be brighter than was originally thought, which is consistent with at least the brightest of them hosting intermediate mass black holes.
New class of black holes discovered
University of Liecester | 01 July 2009
A new class of black hole, more than 500 times the mass of the Sun, has been discovered by an international team of astronomers.

The finding in a distant galaxy approximately 290 million light years from Earth is reported today in the journal Nature.

Until now, identified black holes have been either super-massive (several million to several billion times the mass of the Sun) in the centre of galaxies, or about the size of a typical star (between three and 20 Solar masses).

The new discovery is the first solid evidence of a new class of medium-sized black holes. The team, led by astrophysicists at the Centre d'Etude Spatiale des Rayonnements in France, detected the new black hole with the European Space Agency's XMM-Newton X-ray space telescope.
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It had been long believed by astrophysicists that there might be a third, intermediate class of black holes, with masses between a hundred and several hundred thousand times that of the Sun. However, such black holes had not been reliably detected until now.

This new source, dubbed HLX-1 (Hyper-Luminous X-ray source 1), lies towards the edge of the galaxy ESO 243-49. It is ultra-luminous in X-rays, with a maximum X-ray brightness of approximately 260 million times that of the Sun.

The X-ray signature of HLX-1 and the lack of a counterpart in optical images confirm that it is neither a foreground star nor a background galaxy, and its position indicates that it is not the central engine of the host galaxy.
A Redshift for the Intermediate-mass Black Hole Candidate HLX-1:
Confirmation of its Association with the Galaxy ESO 243-49
- K Wiersema et al Chandra and Swift Follow-up Observations of the Intermediate Mass Black Hole in ESO243-49 - NA Webb et al First evidence for spectral state transitions in the ESO243-49 hyper luminous X-ray source HLX-1 - O Godet et al An intermediate-mass black hole of over 500 solar masses in the galaxy ESO 243-49 - SA Farrell et al

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