Vol 9, No 11 (2009) / Chen

SDSS spectroscopy for blazars in the Fermi LAT bright AGN sample

Zhao-Yu Chen, Min-Feng Gu, Zhong-Hui Fan, Xin-Wu Cao


We have collected all available spectra and photometric data from the SDSS catalog for bright AGNs complied from the first three months of the Fermi large area telescope all-sky survey. Based on the 106 high-confidence and 11 low-confidence associated bright AGN list, the photometry data are collected from SDSS DR7 for 28 sources (12 BL Lacs and 16 FSRQs), two of which are low-confidence associated bright AGNs. Among these 28 SDSS photometric sources, SDSS spectra are available for 20 sources (6 BL Lacs and 14 FSRQs). The black hole masses MBH and the broad line region (BLR) luminosity were obtained for 14 FSRQs by measuring the line-widths and strengths of broad emission lines from the SDSS spectra. The broad emission line measurements of five FSRQs are presented for the first time in this work. The optical continuum emission of these 14 FSRQs is found to be likely dominated by the non-thermal jet emission by comparing the relationship between the broad Mg II line and continuum luminosity to that of radio-quiet AGNs. The black hole mass of the 14 FSRQs ranges from 108.2M to 109.9M, with most of the sources larger than 109M The Eddington ratio Lbol/LEdd ranges from 10-1.5 to ~ 1. This implies that an optically thin, geometrically thick accretion disk may exist in these FSRQs.


galaxies: active—galaxies: nuclei—gamma rays: observations—quasars:emission lines — BL Lacertae objects: general

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