Anticorrelation between the Mass of a Supermassive Black Hole and the Mass Accretion Rate in Type 1 Ultraluminous Infrared Galaxies and Nearby QSOs
Abstract
We discovered a significant anticorrelation between the mass of a supermassive black hole (SMBH), MBH, and the luminosity ratio of infrared to active galactic nuclei (AGN) Eddington luminosity, LIR/LEdd, over 4 orders of magnitude for ultraluminous infrared galaxies with type 1 Seyfert nuclei (type 1 ULIRGs) and nearby QSOs. This anticorrelation (MBH vs. LIR/LEdd) can be interpreted as the anticorrelation between the mass of a SMBH and the rate of mass accretion onto a SMBH normalized by the AGN Eddington rate, M˙BH/M˙Edd. In other words, the mass accretion rate M˙BH is not proportional to that of the central BH mass. Thus, this anticorrelation indicates that BH growth is determined by the external mass supply process, and not the AGN Eddington-limited mechanism. Moreover, we found an interesting tendency for type 1 ULIRGs to favor a super-Eddington accretion flow, whereas QSOs tended to show a sub-Eddington flow. On the basis of our findings, we suggest that a central SMBH grows by changing its mass accretion rate from super-Eddington to sub-Eddington. According to a coevolution scenario of ULIRGs and QSOs based on the radiation drag process, it has been predicted that a self-gravitating massive torus, whose mass is larger than a central BH, exists in the early phase of BH growth (type 1 ULIRG phase) but not in the final phase of BH growth (QSO phase). At the same time, if one considers the mass accretion rate onto a central SMBH via a turbulent viscosity, the anticorrelation (MBH vs. LIR/LEdd) is well explained by the positive correlation between the mass accretion rate M˙BH and the mass ratio of a massive torus to a SMBH.
- Publication:
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The Astrophysical Journal
- Pub Date:
- June 2007
- DOI:
- 10.1086/516563
- arXiv:
- arXiv:astro-ph/0702552
- Bibcode:
- 2007ApJ...661..660K
- Keywords:
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- Black Hole Physics;
- Galaxies: Active;
- Galaxies: Bulges;
- Galaxies: Formation;
- Galaxies: Starburst;
- Infrared: Galaxies;
- Galaxies: Quasars: General;
- Astrophysics
- E-Print:
- 29 pages, 4 figures, accepted for publication in ApJ