A major area of research in X-ray astronomy is the accretion of matter on to black holes and neutron stars in the context of AGN and galactic X-ray binaries. Accretion is an energetic process and can give high luminosities.
Black holes are among the most fascinating phenomena thought to exist in the Universe. A black hole is a region of space in which the gravitational field is so powerful that nothing, not even light, can normally escape.
X-ray astronomy research in Cambridge is carried out by an active X-ray Astronomy group whose research focusses on accretion on to compact objects and the physics of clusters of galaxies.