Observational evidence for young radio galaxies is triggered by accretion disk instability

Abstract

Bolometric luminosities and black hole (BH) masses are estimated by various methods for a sample of young radio galaxies with known ages. We find that the ages are positively correlated with the bolometric luminosities in these young radio galaxies. This positive correlation is consistent with the theoretical prediction based on the radiation pressure instability of accretion disks in Czerny etal. The ages of young radio galaxies are also found to be consistent with the theoretical durations of outbursts in BH mass and accretion rate (in Eddington unit) plane, where the outbursts are assumed to be triggered by the radiation pressure instabilities. Our results provide observational evidence for the radiation pressure instability, which causes limit-cycle behavior, as a physical mechanism that may be responsible for these short-lived young radio galaxies. © 2009. The American Astronomical Society.