Inclinations and Black Hole Masses of Seyfert 1 Galaxies
Abstract
A tight correlation between black hole mass (MBH) and central velocity dispersion (σ) has been found recently for both active and quiescent galaxies. By applying this correlation, we develop a simple method to derive the inclination angles for a sample of 11 Seyfert 1 galaxies that have both measured central velocity dispersions and black hole masses estimated by reverberation mapping. These angles, with a mean value of 36° that agrees well with the result obtained by fitting the iron Kα lines of Seyfert 1 galaxies observed with ASCA, provide further support to the orientation-dependent unification scheme of active galactic nuclei (AGNs). A positive correlation of the inclinations with observed FWHMs of the Hβ line and a possible anticorrelation with the nuclear radio loudness have been found. We conclude that more accurate knowledge of inclinations and broad-line region dynamics is needed to improve the black hole mass determination of AGNs with the reverberation mapping technique.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- November 2001
- DOI:
- 10.1086/324408
- arXiv:
- arXiv:astro-ph/0109283
- Bibcode:
- 2001ApJ...561L..59W
- Keywords:
-
- Black Hole Physics;
- Galaxies: Active;
- Galaxies: Nuclei;
- Galaxies: Seyfert;
- Astrophysics
- E-Print:
- 12 pages including 4 figures, accepted for publication in The Astrophysical Journal Letters