Soft X-Ray Millisecond Variability from an Accreting Neutron Star

The discovery of millisecond variability in the hard (2.530 keV) emission ofneutronstar lowmass xray binaries opened a new window on the study of theaccretion flow and the effects of strong gravitational fields in these systems.We propose to use XMMNewton to search for millisecond variability in the softxray band (0.42.5 keV), which is inaccessible to RXTE. We request twoobservations of 4U 1636536 which has produces strong and narrow kHzquasiperiodic oscillations (QPOs) in hard xrays and is in the continuousviewing zone of the Rossi XRay Timing Explorer. These observations should placeimportant constraints on models of the kHz QPOs. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]