Black-hole-bulge relationship of post-starburst quasars at z ∼ 0.3

Abstract

The M BH-σ* relation has been studied extensively for local galaxies, but to date there have been scarce few direct measurements of stellar velocity dispersions for systems beyond the local universe. We investigate black hole and host galaxy properties of six "post-starburst quasars" (PSQs) at z ∼ 0.3. Spectra of these objects simultaneously display features from the active nucleus including broad emission lines and a host galaxy Balmer absorption series indicative of the post-starburst stellar population. These are the first measurements of σ* in such objects, and we significantly increase the number of directly measured non-local objects on the M BH- σ* diagram. The "PSQs" of our sample fall on or above the locally defined M BH-σ* relation, a result that is consistent with previous M BH- σ* studies of samples at z > 0.1. However, they are generally consistent with the M BH-L bulge relation. Furthermore, their location on the Faber-Jackson relation suggests that some of the bulges may be dynamically peculiar. © 2012. The American Astronomical Society. All rights reserved.