6. Latest results concerning Black Holes and X-ray Astronomy

18 Feb 2004: X-ray outburst announces 'death' of star?

A combination of observations with ROSAT and more recently with XMM-Newton and Chandra have tracked the fading of an explosion in a nearby galaxy. This is possibly the result of a star passing too close to the supermassive black hole in the galaxy's centre and being torn apart and accreted. The energy released was enough to outshine the rest of the galaxy (in X-rays) for several months. After that it slowly faded. Read the official NASA press release here and the ESA press release here. See also the BBC news article here. A pre-print of the paper (published in the Astrophysical Journal) can be found here. If you are really interested you can also read my own paper on this object here

26 Jan 2004: X-ray "halo" echos Gamma-ray Burst

XMM-Newton, has imaged a spectacular set of rings which appear to expand, with a speed a thousand times faster than that of light, around the point in the sky where a Gamma-ray Burst (GRB) took place in early December. This is the first time that such an `echo', has been seen in X-ray wavelengths. The echo forms when the powerful X-rays from the distant GRB, crossed slabs of dust in our Galaxy were scattered. Using the expanding rings the location of this dust and be measured. The official press release by ESA can be found here and the release by PPARC can be found here. The scientific paper can be found here.

17 Sept 2003: Evidence for spinning black holes builds up

9 Sept 2003: Chandra "hears" black hole

24 Mar 2003: New Evidence For Mid-Sized Black Holes

19 Nov 2002: Binary supermassive black holes found

17 Oct 2002: ESA's new Gamma-ray/X-ray mission INTEGRAL launched

8 Oct 2002: Riccardo Giacconi wins the Nobel Prize

Riccardo Giacconi was been awarded one half of the Nobel Prize in Physics "for pioneering contributions to astrophysics, which have led to the discovery of cosmic X-ray sources." In other words, for the development of cosmic X-ray astronomy. More info here. See also the Nobel Prize pages here

3 Oct 2002: The History Of Black Hole X-Ray Jets

The motion of ultra-fast jets shooting out from a candidate black hole star system have now been documented by observations from the orbiting Chandra X-ray Observatory. In 1998, X-ray source XTE J1550-564 underwent a tremendous outburst. Jets of material sent streaming into space at near light-speed impacted existing gas heating it so much it glowed in X-ray light. The panels on the left of the above image show in X-rays that the hot spots have moved out by more than three light years in the time since the explosion, with the left jet recently fading below detectability. The drawing of the right depicts the binary star system that likely produced the X-ray jets, with a normal red star on the left dumping matter into an accretion disk around the black hole on the right. The jets are thought to be emitted along the spin axis of the black hole. Click on the image to see a larger version. Chandra press release available here

9 April 2002: Black Holes play the same tune

The flickering behaviour observed in the X-ray emission from luminous AGN (such as quasars) is essentially the same as the flickering seen from black holes in our Galaxy. The difference is that the massive black holes in quasars are over a millions times bigger, and so the variations are a million times slower. This work is based on observations taken with NASA's RXTE mission by a group in Southampton. See the NAM press release (here) or the original paper (here) for more information.

22 Oct 2001: Evidence for the extraction of energy from a black hole

The X-ray observatory XMM-Newton observed the bright Active Galactic Nucleus (AGN) of the galaxy MCG-6-30-15. The high-quality X-ray spectrum produced from this observation has been studied by an international team and interpreted as showing evidence that energy is being extracted from the black hole itself. (Usually AGN are thought to be powered only by the energy in material falling in to the hole.) The official press releases (complete with some nice pictures) can be found here (NASA version) and here (ESA version). The original paper can be found here.

12 Sept 2001: Path of wandering black hole binary mapped

The motion of the black hole X-ray binary system XTE J1118+480 through our Galaxy has been estimated by an international team. See the press release here. The article describing these results is published in Nature (vol. 413, p139) but can also be read from here.

6 Sept 2001: X-ray variability discovered from the Galactic centre

The X-ray observatory Chandra has observed a "flare" of X-rays from the direction of the Galactic centre. The burst, which lasted for about 3 hours, is possibly the radiation given off as the putative supermassive black hole swallows some surrounding material. See the official NASA press release: http://www1.msfc.nasa.gov/NEWSROOM/news/releases/2001/01-296.html or read the full Nature article here.

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