Black Hole Mass and Eddington Ratio as Drivers for the Observable Properties of Radio-loud and Radio-quiet QSOs
Abstract
Recent studies of black holes in the nuclei of both active and normal galaxies have yielded relationships that permit a physical interpretation of the principal components of the spectra of QSOs. It is shown that principal component (or eigenvector) 1 (PC1) is driven predominantly by L/LEdd, and principal component 2 (PC2) is driven by accretion rate. This results in a PC2 versus PC1 diagram in which lines of constant black hole mass are diagonal. Using a sample consisting of the low-redshift PG objects supplemented by 75 radio-loud QSOs, it is shown that such a diagram effectively distinguishes radio-loud from radio-quiet objects and demonstrates that both narrow-line Seyfert 1 galaxies and broad absorption line QSOs lie at the high L/LEdd extreme, although these two types of objects are well separated in the PC2 direction. A simple picture that ties together physical parameters (black hole mass and Eddington ratio) and classification of active galactic nuclei is presented. Based on the location of core-dominated and lobe-dominated radio-loud QSOs, orientation can be modeled as a third parameter in this scheme, implying an enhancement in the radio flux of core-dominated objects.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- January 2002
- DOI:
- 10.1086/324486
- arXiv:
- arXiv:astro-ph/0109317
- Bibcode:
- 2002ApJ...565...78B
- Keywords:
-
- Galaxies: Nuclei;
- Galaxies: Seyfert;
- Galaxies: Quasars: General;
- Astrophysics
- E-Print:
- 21 pages including 7 figures, accepted for publication in Ap.J