Frédéric Marin20 min

Polarized X-ray emission from accreting compact objects

From X-ray binaries to active galactic nuclei, X-ray emission is thought to originate from accretion onto a compact object. When radiation propagates through the multiple reprocessing regions surrounding the potential well (collapsed star or massive black hole), its electromagnetic properties are modified by scattering and/or interacting with local magnetic fields, affecting its polarization state. The resulting polarization is highly sensitive to the source morphology, the geometry of the reprocessing material, the spacetime through which the X-rays propagate, and the strength of local magnetic fields. As a result, it becomes feasible to probe the vicinity of compact objects using X-ray polarimetry in association with spectral and timing analyzes. Hence, this talk will investigate the topic of X-ray polarimetry, review the physical processes responsible for polarized (reprocessed) emission and show examples of how X-ray polarimetric measurement could be used to constrain the close environment of compact objects.