KTH Physics

XIPE the X-ray Imaging Polarimetry Explorer and new forthcoming opportunities for polarimetry in X-rays

by Paolo Soffitta (IAPS/INAF, Rome)

A5:1003 ()


X-ray polarimetry allows for answering, in a novel way, to questions related to the acceleration phenomena in PWNe, Supernovae and Blazars, to the transport of radiation in plasma embedded in a strong magnetic field like in pulsating X-ray binaries, to questions related to the scattering in a-spherical geometries, like in AGNs and in the molecular clouds located in the galactic center region and, finally, to questions of fundamental physics. Since the dawn of X-ray astronomy it has been clear the value of polarimetry in this energy range but the available techniques have always been the major limitation. Modern photoelectric X-ray polarimeters, based on the Gas Pixel Detector (GPD) technologies, overcame these limitations allowing for a sensitive measurement on hundreds of sources. Two forthcoming missions exploit the GPD technology: XIPE (the X-ray Imaging Polarimetry Explorer) now in the study phase for ESA and IXPE (the Imaging X-ray Polarimetry Explorer) now in phase A study for NASA in competition with another polarimetry mission with an alternative technology. XIPE will be operated as a conventional X-ray observatory but providing polarimetry simultaneously to the usual imaging, temporal and spectral information. This is made possible by its unique payload configuration consisting of three GPDs at the focus of three large, albeit low-weight, X-ray telescopes and fitting in the Vega launcher. In this talk I will review the major aspects involved with this kind of measurement, the scientific targets, the mission profile and payload of upcoming opportunities.