The potential of X-ray polarimetry
Abstract
Up-scattering of low-energy photons by Inverse Compton processes in a hot gas of electrons (i.e. Comptonization) is a common astrophysical mechanism particularly important in accreting systems like X-ray binaries (XRBs) and Active Galactic Nuclei (AGN). Polarization signals produced by scattering strongly depend on the optical thickness and geometry of the scattering medium as well as on the observer's viewing angle. The polarization degree and angle can be used to constrain, for example, the still unknown parameters which characterize the hot corona responsible for the production of X-ray radiation in AGN or the dominant mechanism responsible for the broadening of the Iron K-alpha emission line whose origin is still a matter of debate in the case of low mass X-ray binaries with a neutron star. Conducting accurate Monte Carlo simulations we show the potential of X-ray polarimetry, a new perspective of X-ray astronomy. The spectroscopic part of our results can already be exploited today in the light of XMM-Newton and Chandra data and is even more appealing in the perspective of data from NuStar and future X-ray missions.
- Publication:
-
The X-ray Universe 2014
- Pub Date:
- July 2014
- Bibcode:
- 2014xru..confE.194T