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| Paper: |
Accretion and Jet Activities in Young Radio Galaxies |
| Volume: |
446, Galaxy Evolution: Infrared to Millimeter Wavelength Perspective |
| Page: |
161 |
| Authors: |
Wu, Q. |
| Abstract: |
We estimate the black hole (BH) mass and bolometric luminosity for a
sample of young
radio galaxies [gigahertz-peaked spectrum (GPS) and compact steep-spectrum
(CSS) sources]. We find that the average BH mass of
these young radio galaxies <log Mbh> ≅ 8.3, which
is less than that of radio loud QSOs and low redshift radio galaxies
(<log Mbh> ≅ 9.0). The CSS/GPS sources have
relatively high Eddington ratios with average ratio <log Lbol/LEdd>= –0.56, which are similar to those of narrow
line Seyfert 1 galaxies (NLS1s). The smaller BH mass and higher
accretion rate of CSS/GPS sources suggest that they may not only be
in the early stage of radio activities, but also in the early stage
of their accretion activities. We find that the ages are positively
correlated with the bolometric luminosities for a sample of young
radio galaxies with estimated ages,
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. |
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