Astrophysics Luncheon Seminar
Distant Quasars: Black Hole Mass Growth and Dust Emission
Presented by Hyunsung Jun
Jet Propulsion Laboratory, California Institute of Technology
Monday, March 2, 2015
12:00 noon in 169-336
I will report on the early evolution of active galactic nuclei (AGNs) through the growth of black hole (BH) mass and their dust emission strength. Using a sample of 155 luminous quasars at 3<z<6 observed with AKARI, we measured BH masses from rest-frame optical spectra, extending the scaling relations between AGN continuum and line luminosities to luminous, high redshift quasars. We also investigated the BH mass estimator scaling relations of H-alpha, MgII, and CIV compared to the H-beta BH mass estimator. This work provides constraint on the massive end of BH mass growth at high redshift. Next, we identified and characterized a population of luminous dust-poor quasars at z<5 - quasars showing little IR emission from the AGN dusty structure. Compiling a rest-frame UV to IR library of 41,000 optically selected type-1 quasars, we fitted the broad-band spectral energy distributions (SEDs) with accretion disk and dust model components. We find that 0.6% of the sample is hot-dust-poor, and present their observed properties.