The Blueshift of the C iv Broad Emission Line in QSOs

For the sample from Ge et al. of 87 low-z Palomar-Green quasi-stellar objects (QSOs) and 130 high-z QSOs (0 < z < 5) with H beta-based single-epoch supermassive black hole masses, we perform a uniform decomposition of the C IV lambda 1549 broad-line profile. Based on the rest frame defined by the [O III] lambda 5007 narrow emission line, a medium-strong positive correlation is found between the C IV blueshift and the luminosity at 5100 angstrom or the Eddington ratio L-Bol/L-Edd. A medium-strong negative relationship is found between the C IV blueshift and C IV equivalent width. These results support the postulation where the radiation pressure may be the driver of C IV blueshift. There is a medium-strong correlation between the mass ratio of C IV-based to H beta-based M-BH and the C IV blueshift, which indicates that the bias for C IV-based M-BH is affected by the C IV profile.National Key Research and Development Program of China [2017YFA0402703]; National Science Foundations of China [11373024, 11233003, 11873032]This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu