The Relationship Between Black Hole Mass and Velocity Dispersion in Seyfert 1 Galaxies

• Published in: The Astrophysical journal 2004-11, Vol.615 (2), p.652-661
• Main Authors: Nelson, Charles H, Green, Richard F, Bower, Gary, Gebhardt, Karl, Weistrop, Donna
• Format: Article
• Language: English
• Subjects: Active and peculiar galaxies (including bl lacertae objects, blazars, seyfert galaxies, markarian galaxies, active galactic nuclei); Astronomy; Earth, ocean, space; Exact sciences and technology; Quasars; Quasars. Active or peculiar galaxies, objects, and systems; Stellar systems. Galactic and extragalactic objects and systems. The universe
• ISSN: 0004-637X; 1538-4357
• DOI: 10.1086/424657

Black hole masses in active galactic nuclei are difficult to measure using conventional dynamical methods but can be determined using the technique of reverberation mapping. However, it is important to verify that the results of these different methods are equivalent. This can be done indirectly, using scaling relations between the black hole and the host galaxy spheroid. For this purpose, we have obtained new measurements of the bulge stellar velocity dispersion, sigma *, in Seyfert 1 galaxies. These are used in conjunction with the M sub(BH)- sigma * relation to validate nuclear black hole masses, M sub(BH), in active galaxies determined through reverberation mapping. We find that Seyfert galaxies follow the same M sub(BH)- sigma * relation as nonactive galaxies, indicating that reverberation mapping measurements of M sub(BH) are consistent with those obtained using other methods. We also reconsider the relationship between bulge absolute magnitude, M sub(bul), and black hole mass. We find that Seyfert galaxies are offset from nonactive galaxies, but that the deviation can be entirely understood as a difference in bulge luminosity, not black hole mass; Seyfert galaxy hosts are brighter than normal galaxies for a given value of their velocity dispersion, perhaps as a result of younger stellar populations.