The black hole mass galaxy bulge relationship for QSOs in the SDSS DR3
Résumé
We investigate the relationship between black hole mass, MBH, and host galaxy velocity dispersion, sigma*, for QSOs in Data Release 3 of the Sloan Digital Sky Survey. We derive MBH from the broad Hbeta line width and continuum luminosity, and the bulge stellar velocity dispersion from the [O III] narrow line width ( sigma[O III] ). For higher redshifts, we use Mg II and [O II] in place of Hbeta and [O III]. For redshifts z < 0.5, our results agree in the mean with the MBH- sigma* relationship for nearby galaxies. For 0.5 < z < 1.19, we find an apparent departure from the MBH- sigma* relationship with redshift such that bulges are too small for their black holes. However, some of this apparent trend can be attributed to observational biases. Accounting for these biases, we find an upper limit of ˜0.3 dex on any evolution in the MBH- sigma* relationship between now and redshift z ≈ 1.