English

The $M_\bullet$-$\sigma_e$ relation for local type 1 AGNs and quasars

Astrophysics of Galaxies 2024-09-16 v1

Abstract

We analyzed MUSE observations of 42 local z<0.1z<0.1 type 1 active galactic nucleus (AGN) host galaxies taken from the Palomar-Green quasar sample and the close AGN reference survey. Our goal was to study the relation between the black hole mass (MM_\bullet) and bulge stellar velocity dispersion (σe\sigma_e) for type 1 active galaxies. The sample spans black hole masses of 106.0109.2M10^{6.0}-10^{9.2}\,M_\odot, bolometric luminosities of 1042.91046.010^{42.9}-10^{46.0}\,erg\,s1^{-1}, and Eddington ratios of 0.006-1.2. We avoided AGN emission by extracting the spectra over annular apertures. We modeled the calcium triplet stellar features and measured stellar velocity dispersions of σ=60230\sigma_* = 60-230\,km\,s1^{-1} for the host galaxies. We find σ\sigma_* values in agreement with previous measurements for local AGN host galaxies, but slightly lower compared with those reported for nearby X-ray-selected type 2 quasars. Using a novel annular aperture correction recipe to estimate σe\sigma_e from σ\sigma_* that considers the bulge morphology and observation beam-smearing, we estimate flux-weighted σe=60250\sigma_e = 60-250\,km\,s1^{-1}. If we consider the bulge type when estimating MM_\bullet, we find no statistical difference between the distributions of AGN hosts and the inactive galaxies on the MσeM_\bullet - \sigma_e plane for M108MM_\bullet \lesssim 10^8\,M_\odot. Conversely, if we do not consider the bulge type when computing MM_\bullet, we find that both distributions disagree. We find no correlation between the degree of offset from the MσeM_\bullet - \sigma_e relation and Eddington ratio for M108MM_\bullet \lesssim 10^8\,M_\odot. The current statistics preclude firm conclusions from being drawn for the high-mass range. We argue these observations support notions that a significant fraction of the local type 1 AGNs and quasars have undermassive black holes compared with their host galaxy bulge properties.

Keywords

Cite

@article{arxiv.2409.08893,
  title  = {The $M_\bullet$-$\sigma_e$ relation for local type 1 AGNs and quasars},
  author = {J. Molina and L. C. Ho and K. K. Knudsen},
  journal= {arXiv preprint arXiv:2409.08893},
  year   = {2024}
}

Comments

18 pages, plus Appendix. 15 Figures, 4 Tables. Accepted for publication on A&A

R2 v1 2026-06-28T18:43:49.308Z