Intensity and Polarization Characteristics of Extended Neutron Star Surface Regions

Abstract The surfaces of neutron stars are sources strongly polarized soft X-rays due to the presence strong magnetic fields. Radiative transfer mediated by electron scattering and free–free absorption is central defining local surface anisotropy polarization signatures. Scattering transport influenced complicated interplay between linear circular polarizations. This complexity has been captured in a sophisticated Thomson simulation we recently developed model outer layers fully ionized atmospheres such compact objects, heretofore focusing on case studies localized regions. Yet, interpretation observed intensity pulse profiles their efficacy constraining key star geometry parameters critically dependent upon adding up emission from extended In this paper, intensity, anisotropy, characteristics atmospheres, spanning considerable ranges colatitudes, determined using our simulation. These constitute convolution varied properties Stokes parameter information at disparate locales with different field strengths directions relative zenith. Our analysis includes full general relativistic propagation light an observer infinity. array for presented highlights how powerful probes stellar possible. Significant phase-resolved degrees range 10%–60% realized when summing over variety directions. results provide important background observations be acquired NASA’s new Imaging X-ray Polarimetry Explorer polarimetry mission.