2017AJ....153...55S

We analyze the emission line profiles detected in deep optical spectra of quasars to derive the mass of their super-massive black holes (SMBH) following the single-epoch virial method. Our sample consists in six radio-loud (RL) quasars and four radio-quiet (RQ) quasars. We carefully fit a broad and narrow Gaussian component for each emission line in both the Hβ (10 objects) and Hα regions (5 objects). A very good agreement of the derived SMBH masses, M_SMBH, is found using the fitted broad Hβ and Hα emission lines. We compare our M_SMBH results with those found by previous studies. We study the relationship between the M_SMBH of the quasar and the stellar velocity dispersion, σ_*, of the host galaxy. We use the measured M_SMBH and σ_* to investigate the M_SMBH-σ_* relation for both the RL and radio-quiet subsamples. Besides the scatter, we find a good agreement between radio-quiet quasars and AGN+quiescent galaxies and between RL quasars and AGN. Our analysis does not support the hypothesis of using σ([O iii] λ5007) as a surrogate for stellar velocity dispersions in high-mass, high-luminosity quasars. We also investigate the relationship between the 5 GHz radio-continuum luminosity, L_5GHz, of the quasar host galaxy with both M_SMBH and σ_*. We do not find any correlation between L_5GHz and M_SMBH, although we observe a trend that galaxies with larger stellar velocity dispersions have larger L_5GHz. Using the results of our fitting for the narrow emission lines of [O iii] λ5007 and [N ii] λ6583 we estimate the gas-phase oxygen abundance of six quasars, being sub-solar in all cases.