Stellar and gaseous velocity dispersions in type II AGNs at 0 . 3 < z < 0 . 83 from the Sloan Digital Sky Survey

We apply the stellar population synthesis code by Cid Fernandes et al. to model the stellar contribution for a sample of 209 type II AGNs at redshifts 0.3 < z < 0.83 from the Sloan Digital Sky Survey. The reliable stellar velocity dispersions (σ∗) are obtained for 33 type II AGNs with significant stellar absorption features. According to the L[OIII] criterion of 3 × 10 L , 20 of which can be classified as type II quasars. We use the formula of Greene & Ho to obtain the corrected stellar velocity dispersions (σ ∗). We also calculate the supermassive black holes masses from σ c ∗ in these higherredshift type II AGNs. The [O III] luminosity is correlated with the black hole mass, and no correlation is found between the [O III] luminosity and the Eddington ratio. Three sets of two-component profiles are used to fit multiple emission transitions ([O III]λλ4959, 5007 and [O II]λλ3727, 3729) in these 33 stellar-light subtracted spectra. We also measure the gas velocity dispersion (σg) from these multiple transitions, and find that σg can trace σ ∗ (although with considerable scatter), which confirms that the gaseous kinematics of narrow line regions in these type II quasars are primarily dominated by the gravitational potential of the bulge. The distribution of < σg/σ ∗ > is 1.24±0.76 for the core [O III] line and 1.20±0.96 for the [O II] line, which suggests that σg of the core [O III] and [O II] lines can trace σ ∗ within about 0.1 dex in the logarithm of σ ∗. For the secondary driver, we find that the deviation of σg from σ c ∗ is correlated with the Eddington ratio.