Speaker
Description
X-ray timing and broadband spectroscopy have been the main methods for studying the rich and complex phenomenology of neutron stars with weak magnetic fields for a long time. Nowadays, X-ray polarimetry offers the missing, independent set of observables that are directly relevant to comprehending the geometry and nature of the emission regions: polarization degree and angle. This allows for breaking the degeneracies due to the fact that different geometries and physical conditions might yield equivalent spectral and timing signatures. Some of the main results obtained in this frame by using the Imaging X-ray Polarimetry Explorer (IXPE) will be reported in this talk. X-ray polarization seems to vary in response to the intensity and spectral hardness associated with possible variations in the accretion rate and possibly to the geometry of the emitting regions. The possible contribution from an extended accretion-disk corona or a disk-wind component, the spreading layer, and the boundary layer is also discussed.