Black Hole Spin Survey of Radio-quiet AGN

High energy X-ray spectra of active galactic nuclei (AGN) emitted from accretion flows around supermassive black holes (SMBH) offer a novel means to study the general relativistic strong-field gravity impacts of black holes. Nearby Seyfert type I active galaxies contain the best known radio-quiet AGN for an X-ray survey due to low levels of obscuration. In particular, highly ionized gaseous outflows measured from H-like and Helike iron absorption lines in AGN are mostly emitted from the areas close to the innermost stable circular orbit (ISCO) regions of the accretion disk around the SMBH, which are affected by general relativistic strong-field gravity of the spinning supermassive black hole. Relativistically broadened fluorescent K-alpha iron lines emitted from nearby ISCO regions can be used to constrain the black hole spins, which will help us understand how SMBHs impact on their host galaxies and formation of large-scale galactic outflows. We have not yet fully investigated whether physical and kinematic properties of highly-ionized ultra-fast outflows are correlated with SMBH angular momenta as predicted by the theory of general relativity.

We therefore propose to advance our understanding of the physics of supermassive black holes in radio-quiet AGN by constraining the black hole spins of a sample of radio-quiet Type I AGN (Seyfert 1.0, 1.2, and 1.5) with well-identified highly-ionized ultra-fast outflows based on H-like and He-like Fe absorption lines, and to explore possible correlations of the kinematic and physical conditions of X-ray ultra-fast outflows with black hole spins measured from relativistically broadened K-alpha iron lines at 6.4 keV (rest frame) and Compton reflection humps above 10 keV. A recently developed relativistic disk reflection model will allow us to accurately constrain the spin parameters of SMBHs in these objects. Our SMBH spin measurements will be released in an online database and their results will be discussed in details in our peer-reviewed publications. Our final goal is to compile a spin database, together with the black hole masses recently determined from the reverberation mapping campaigns, that can be used to explore possible correlations of the SMBH angular momenta with kinematic and physical properties of ultra-fast outflows. This study will be implemented using X-ray archival data collected by NuSTAR (NASA mission), Suzaku (NASA & JAXA joint mission), and XMM-Newton space telescopes over the past decade.