The Polarization from Relativistic Astrophysical X-ray Sources (PRAXyS) Mission

The PRAXyS mission, currently in a NASA Phase A study, will be the first mission dedicated to X-ray Polarimetry in the 2-10 keV band. Polarization is an expected feature of non-symmetric sources; most of the bright X-ray sources are associated with black holes and neutron star systems or other sources which are intrinsically asymmetric. Propagation through the intense gravitational and magnetic fields near these sources introduces additional polarization signatures. Polarization is thus a probe of structure on scales many orders of magnitude to small for any current imaging capability. PRAXyS will survey the polarization characteristics of emission from stellar mass black holes in our galaxy, the super massive black holes at the heart of active galaxies and blazars, neutron stars powered by rotation, accretion, or magnetic fields, and other high energy sources. We present measured performance characteristics of the PRAXyS instrumentation that provides both the estimated sensitivity to polarization and the upper limits to instrumental systematic effects. We also present the opportunities for community involvement via rapid data release and vigorous guest observer and theory programs.