We create a baseline of the black hole ( BH ) mass ( M _ { BH } ) – stellar-velocity dispersion ( \sigma ) relation for active galaxies , using a sample of 66 local ( 0.02 < z < 0.09 ) Seyfert-1 galaxies , selected from the Sloan Digital Sky Survey ( SDSS ) .
Analysis of SDSS images yields AGN luminosities free of host-galaxy contamination , and morphological classification .
51/66 galaxies have spiral morphology .
28 bulges have Sérsic index n < 2 and are considered candidate pseudo bulges , with eight being definite pseudo bulges based on multiple classification criteria met .
Only 4/66 galaxies show signs of interaction/merging .
High signal-to-noise ratio Keck spectra provide the width of the broad H \beta emission line free of FeII emission and stellar absorption .
AGN luminosity and H \beta line widths are used to estimate M _ { BH } .
The Keck-based spatially-resolved kinematics is used to determine stellar-velocity dispersion within the spheroid effective radius ( \sigma _ { spat,reff } ) .
We find that \sigma can vary on average by up to 40 % across definitions commonly used in the literature , emphasizing the importance of using self-consistent definitions in comparisons and evolutionary studies .
The M _ { BH } - \sigma relation for our Seyfert-1 galaxy sample has the same intercept and scatter as that of reverberation-mapped AGNs as well as that of quiescent galaxies , consistent with the hypothesis that our single epoch M _ { BH } estimator and sample selection do not introduce significant biases .
Barred galaxies , merging galaxies , and those hosting pseudo bulges do not represent outliers in the M _ { BH } - \sigma relation .
This is in contrast with previous work , although no firm conclusion can be drawn on this matter due to the small sample size and limited resolution of the SDSS images .