APT2 - Supermassive Black Holes |
Speaker_ |
Nowak, Michael |
Talk _ |
Three Broad Band, High Resolution Views of Galactic Black Holes |
Abstract _ |
Very broadly speaking, black holes present two extremes of spectral states: spectrally X-ray soft, radio quiet, with minimal variability, or spectrally X-ray hard, radio loud, with great variablity. Various "transitions" between these extremes, as well as "intermediate" states, are in fact also observed, but these extremes define some of the basic questions. What is the role of the jet in producing the X-ray spectra? Does an accretion disk extend down to the innermost region near the black hole event horizon? Do we see evidence of the disk receding in state transitions? What do broad Fe fluroescence lines tell us about relativity? As a means of reviewing some of these basic questions, I will present broad band RXTE-Chandra and RXTE-XMM data of 3 objects: Cyg X-1, GX 339-4, and 4U 1957+11, that represent a "classic hard state", a "transition state", and a "pure soft state". (Many of these observations have simultaneous radio and/or optical as well.) I will discuss the implications that each of these have for the above questions. |