Astronomers pave way for black hole census

[Rick]

Russian astronomers have begun work that will allow them to work out how many black holes there are in the Universe.

The research team at the Space Research Institute in Moscow is using the European Space Agency's (ESA) gamma ray observatory, Integral, to measure the X-ray and gamma ray background radiation that permeates the universe.

More: http://www.theregister.co.uk/2006/09/07/black_hole_census/