Events in Physics
Andy Young (Bristol University)
Title: X-ray echoes from active galaxies
Abstract: X-ray spectroscopy provides a unique view of the innermost workings of accretion flows onto black holes. When coupled with variability studies one can, in principle, determine the geometry of the inner accretion flow, corona and even test general relativity in the strong field regime close to a black hole. I will introduce the use X-ray spectroscopy, and "broad iron lines" in particular, to study accretion discs around black holes. I will then explain why X-ray echo (reverberation) mapping is in principle such a powerful technique for studying the innermost regions of the accretion flow, and how in practice it is possible. Throughout the talk I will present some recent (and not so recent) results, and end by discussing the future direction of my work in this area.