A sample of Type 1 quasars with CIV & Hbeta data

We investigate the relationship between emission-line properties and accretion rate for a sample of 230 "ordinary" type 1 quasars and 18 WLQs at z<0.5 and 1.5<z<3.5 that have rest-frame ultraviolet and optical spectral measurements. We apply a correction to the H{beta}-based black hole mass (M_BH_) estimates of these quasars using the strength of the optical FeII emission.

We confirm previous findings that WLQs' M_BH_ values are overestimated by up to an order of magnitude using the traditional broad-emission-line region size-luminosity relation. With this MBH correction, we find a significant correlation between H{beta}-based Eddington luminosity ratios and a combination of the rest-frame CIV equivalent width and CIV blueshift with respect to the systemic redshift. This correlation holds for both ordinary quasars and WLQs, which suggests that the two-dimensional CIV parameter space can serve as an indicator of accretion rate in all type 1 quasars across a wide range of spectral properties.