We have measured the stellar velocity dispersions ( \sigma _ { * } ) and estimated the central black hole ( BH ) masses for over 900 broad-line active galactic nuclei ( AGNs ) observed with the Sloan Digital Sky Survey .
The sample includes objects which have redshifts up to z = 0.452 , high quality spectra , and host galaxy spectra dominated by an early-type ( bulge ) component .
The AGN and host galaxy spectral components were decomposed using an eigenspectrum technique .
The BH masses ( M _ { BH } ) were estimated from the AGN broad-line widths , and the velocity dispersions were measured from the stellar absorption spectra of the host galaxies .
The range of black hole masses covered by the sample is approximately 10 ^ { 6 } < M _ { BH } < 10 ^ { 9 } M _ { \sun } .
The host galaxy luminosity-velocity dispersion relationship follows the well-known Faber-Jackson relation for early-type galaxies , with a power-law slope 4.33 \pm 0.21 .
The estimated BH masses are correlated with both the host luminosities ( L _ { H } ) and the stellar velocity dispersions ( \sigma _ { * } ) , similar to the relationships found for low-redshift , bulge-dominated galaxies .
The intrinsic scatter in the correlations are large ( \sim 0.4 dex ) , but the very large sample size allows tight constraints to be placed on the mean relationships : M _ { BH } \propto L _ { H } ^ { 0.73 \pm 0.05 } and M _ { BH } \propto \sigma _ { * } ^ { 3.34 \pm 0.24 } .
The amplitude of the M _ { BH } - \sigma _ { * } relation depends on the estimated Eddington ratio , such that objects with larger Eddington ratios have smaller black hole masses than expected at a given velocity dispersion .
While this dependence is probably caused at least in part by sample selection effects , it can account for the intrinsic scatter in the M _ { BH } - \sigma _ { * } relation , and may tie together the accretion rate with physical properties of the host bulge component .
We find no significant evolution in the M _ { BH } - \sigma _ { * } relation with redshift , up to z \approx 0.4 , after controlling for possible dependencies on other variables .
Interested readers can contact the authors to obtain the eigenspectrum decomposition coefficients of our objects .