Observational Evidence for Young Radio Galaxies are Triggered by
  Accretion Disk Instability
  The 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, which is consistent with theoretical prediction
based on radiation pressure instability of accretion disk in Czerny et al. 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 the 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.
