Presentation #316.02D in the session AGN and Quasars V.
The mass and accretion rate is essential to quantify the growth of the black holes, their evolution, and their impact on the host galaxies. Recent reverberation-mapped active galactic nuclei (AGNs) show that the highest accretion rate objects have a systematic smaller broad-line region (BLR) radius, 3-8 times smaller than predicted by traditional radius-luminosity (R–L) relationships. I examined the X-ray and optical-UV (OUV) properties of a dozen super-Eddington accreting black holes (SEAMBHs) that show extreme deviation from the canonical R-L relationship. Their X-ray properties may be diagnostic of structural changes in their accretion disks that may explain such behavior. I will present new Chandra X-ray and follow-up OUV observations of these SEAMBHs. They indeed have a steep hard X-ray photon index, Γ, and demonstrate a steeper power-law slope, αox, and these properties correlate with accretion rate. As highly accreting AGNs have a smaller BLR radius than previously realized, they need modified prescriptions for single-epoch virial black hole mass estimates. A new R-L relationship by Du & Wang (2019) corrects for accretion rate biases by incorporating the flux ratio of optical Fe II to Hβ. I will present the result of using this R-L relationship to estimate the black hole mass and accretion rate parameters of quasars in a wide range of redshifts. Failure to use a Fe-corrected R-L relationship results in the virial mass overestimated by a factor of two, on average, and up to an order of magnitude for highly accreting black holes.