NASA | MSFC | SAO | Chandra X-ray Observatory | 2016 Oct 19
[c][attachment=0]ngc5128[1].gif[/attachment][/b][/c][hr][/hr]This image shows the location of a remarkable source that dramatically flares in X-rays unlike any ever seen. Along with another similar source found in a different galaxy, these objects may represent an entirely new phenomenon, as reported in our latest press release.
These two objects were both found in elliptical galaxies, NGC 5128 (also known as Centaurus A) shown here and NGC 4636. In this Chandra X-ray Observatory image of NGC 5128, low, medium, and high-energy X-rays are colored red, green, and blue, and the location of the flaring source is outlined in the box to the lower left.
Both of these mysterious sources flare dramatically - becoming a hundred times brighter in X-rays in about a minute before steadily returning to their original X-ray levels about an hour later. At their X-ray peak, these objects qualify as ultraluminous X-ray sources (ULXs) that give off hundreds to thousands of times more X-rays than typical X-ray binary systems where a star is orbiting a black hole or neutron star.
Five flares were detected from the source located near NGC 5128, which is at a distance of about 12 million light years from Earth. A movie showing the average change in X-rays for the three flares with the most complete Chandra data, covering both the rise and fall, is shown in the inset.
The source associated with the elliptical galaxy NGC 4636, which is located about 47 million light years away, was observed to flare once. ...
Ultraluminous X-ray bursts in two ultracompact companions to nearby elliptical galaxies - Jimmy A. Irwin et al
- Nature 538():356 (20 Oct 2016) DOI: 10.1038/nature19822