AGN on the Beach of X-ray Polarimetry
Dawoon Edwin Kim
X-ray polarimetry is a crucial diagnostic tool to investigate the disk-corona scattering geometry in Active Galactic Nuclei (AGN) and the particle acceleration mechanisms in AGN jets. However, only recently, thanks to the sensitivity of the detectors on board the Imaging X-ray Polarimetry Explorer (IXPE), it became possible to perform X-ray polarimetric measurements of extragalactic sources. In this talk, we will summarize the remarkable discoveries achieved thanks to the new window of X-ray polarimetry, with a focus on the geometry in the disk, wind, and torus in radio-quiet AGN, as well as the acceleration mechanisms in relativistic jets from radio-loud AGN. In particular, we will present the results of recent IXPE observations of NGC 4151 (a prototypical Seyfert 1) and Mrk 421 (a prototypical blazar). Finally, we will discuss future perspectives for a deeper understanding of the geometrical and dynamical properties of AGN.