Definitive Observations of an Accretion Disk Wind in the Quasar MR 2251-178

The bright, nearby QSO MR 2251178 was the first AGN where a warm absorber was detected. Subsequent observations have shown that there are at least two warm absorber components; a low ionisation soft Xray absorber and a putative high velocity (0.07c) wind. We propose a deep (336 ks total) observation of MR 2251178 in order to determine the origin of the outflow. Our goals are; (i) to establish the nature of the high ionisation absorber, e.g. as part of adisk wind, through high S/N observations in the iron K band and (ii) obtain a high resolution RGS spectrum of the soft Xray absorber. Together with our recently approved large Chandra/HST project, this will allow us to deduce the kinematics, location and energetics of the outflow to unprecedented accuracy. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]