Tsukuba Uchu Forum

140th Uchu Forum


Atsushi Tanimoto

Kagoshima University

 Active Galactic Nucleus (AGN) is a phenomenon in which the accretion of mass onto a supermassive black hole (SMBH) converts its gravitational energy into radiant energy, causing the center of the galaxy to glow with a solar intensity of about $10^{9}$. AGNs emit gamma rays from radio waves, which have been observed at various wavelengths. Recently, the Atacama Large Millimeter/submillimeter Array (ALMA) submillimeter interferometer has made it possible to directly image the pc-scale structure of AGNs. However, the structure inside the pc scale is still not well understood. In this study, we investigated the inner structure of AGN by using X-ray polarization observation. This is because, in the case of X-ray polarization observation, the observed polarization intensity and polarization angle strongly depend on the density and geometrical structure of the material surrounding the AGN. In fact, in 2022, the X-ray astronomy satellite Imaging X-ray Polarimetry Explorer (IXPE) will detect X-ray polarization from the Circinus galaxy, a nearest-neighbor Seyfert-2 galaxy, for the first time in the world. In this talk, I will introduce the basics (history of AGN observations, classification, unified model, etc.) and the latest research (radiation-driven fountain model based on 3-D radiation fluid calculations, X-ray polarimetry calculations based on radiation-driven fountain model). Image