Speaker
Description
We present central stellar velocity dispersion measurements for 158 type 1 AGNs from the second data release of the Swift/BAT AGN Spectroscopic Survey (BASS DR2) with a redshift cut-off z < 0.08. A total number of 297 type 1 AGN spectra are fit for obtaining two independent measurements from the Ca II H+K + Mg I region (3880 - 5550 ̊A) and the calcium triplet region (8350-8750 ̊A). The resulting σCaT estimates are found to be in the range: 73 ≤ σCaT ≤ 278 km s−1, whereas the σCaH+K+M gI estimates are found to be in the range: 82 ≤ σCaH+K+M gI ≤ 272 km s−1, for our AGN sample. We show that both σ estimates are very consistent with each other with an average difference of 0.03 dex. Using the BASS DR2 MBH archive and our σ measurements, we present one of the largest MBH - σ relation investigations for type 1 AGNs. We demonstrate that extinction in BLR causes under-estimation of black hole masses (MBH), accordingly, over-estimation of Eddington ratios (log λEdd). We do not find a significant trend between the offset from the MBH - σ relation versus star-formation and the core radio AGN luminosities. Interestingly, we report that AGNs with relatively higher log λEdd show higher offset implying that their super-massive black holes still need to grow to keep up with their host-galaxy growth. We conclude that the offset from MBH - σ relation is still strong for AGNs relative to elliptical/classical bulge-hosting galaxies, and using a specified AGN MBH - σ relation is a better approach for obtaining black hole masses of AGN populations.
