X-ray polarimetry with IXPE
Polarimetry in the X-ray band would help us answer many open questions on the nature of emission processes and geometry in many celestial sources. However, the field of X-ray polarimetry has been dormant for decades, with only one object, the Crab Nebula, having a significant detection so far. This condition is about to change thanks to NASA-ASI Imaging X-ray Polarimetry Explorer (IXPE), launching in December 2021. IXPE will perform, for the first time, spatially resolved X-ray polarimetry and will provide sensitive measurements for objects of all major classes of X-ray sources in the 2 – 8 keV band. In this talk I will give an overview of the mission and its characteristics. I will present the instrument at its heart, the Gas Pixel Detector imaging polarimeter, and discuss the importance of its calibration both in orbit and on ground. I will show some of the IXPE scientific targets and goals: from the study of the corona geometry and emission process in Galactic Black Hole binaries and Active Galactic Nuclei, to the determination of magnetic field orientation and turbulence level in supernova remnants, to the investigation of the recent past of the Milky Way Supermassive Black Hole, Sgr A*.