Is a newly discovered, exotic class of Black Holes sending X-rays in our direction?
Are some very bright sources of X-rays in local galaxies coming from massive Black Holes that were not suspected to exist? Is it possible that Black Holes of a few tens to a few hundreds times the mass of the sun are now being detected by the newest telescope that looks in X-rays? With the launch of the Chandra X-ray Observatory aboard the shuttle a few years ago, it has become possible to detect sources of X-rays in distant galaxies with unprecedented clarity and sensitivity. With this new observational tool, astronomers have discovered a new class of objects that they call "Ultra-Luminous X-ray sources" (ULXs) because they are much more luminous than the common X-ray sources found in galaxies previously. These latter are binary stars containing either a neutron star or a black hole with a mass just a few times that of the sun. The normal sequence for the formation and evolution of stars does not lead to the production of Black Holes with masses of a hundred times that of the sun. Exotic processes are needed. Astronomers are racing to determine the true nature of the ULXs using various measurements and analysis of the X-rays coming from the ULXs. They are trying to make connections between the sources of these X-rays and objects that can be seen in visible light. If the source is found to be in a binary system then the properties of the orbit can be measured. Come and share the excitement and frustration of research into the nature of the ULXs.