Jets and accretion processes in active galactic nuclei: further clues

Celotti, A.; Padovani, P.; Ghisellini, G.

doi:10.1093/mnras/286.2.415

Cited by 268 publications

(316 citation statements)

References 27 publications

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“…(iv) It is well know that the broad-line luminosity can be taken as an indicator of the accretion power of the source (Celotti et al 1997). From our results, we can see that the correlation between broad line luminosity and jet power is significant, which supports that jet power has a close link with accretion.…”

Section: Conclusion and Discussionsupporting

confidence: 71%

“…Secondly, if the observed light curve was found to have only one maximum and one minimum, we defined twice the time interval between this maximum and minimum as the minimum timescale for flux variations (Xie et al 2004a). Celotti et al (1997) considered the sample of radio loud AGNs, which includes 105 sources with VLBI angular diameter data available in the literature. The broad-line luminosity given in Celotti,Padovani & Ghisellini (1997) were derived by scaling several strong emission lines to the quasar template spectrum of Francis et al (1991), and used Lyα as a reference.…”

Section: The Sample Of Blazarsmentioning

confidence: 99%

“…Celotti et al (1997) considered the sample of radio loud AGNs, which includes 105 sources with VLBI angular diameter data available in the literature. The broad-line luminosity given in Celotti,Padovani & Ghisellini (1997) were derived by scaling several strong emission lines to the quasar template spectrum of Francis et al (1991), and used Lyα as a reference. Francis et al (1991) set Lyα flux contribution to 100, the relative weight of Hα, Hβ, MgII, and CIV lines respectively, to 77, 22, 34, and 63.…”

Section: The Sample Of Blazarsmentioning

confidence: 99%

“…It is well known that the broad-line luminosity is also an important parameter for understanding the nature of blazars besides the intrinsic bolometric luminosity. The broad-line luminosity can be taken as an indicator of the accretion power of the source (Celotti et al 1997;Cao and Jiang 1999). Cao and Jiang (1999) found a significant correlation between radio and broad line luminosity for a sample of radio loud quasars.…”

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confidence: 99%

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Jet/accretion and unification for FSRQs/FRII and BL Lac objects/FRI radio galaxies

Chen

Zhang

et al. 2015

Astrophys Space Sci

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We compiled a sample of 24 flat-spectrum radio quasars (FSRQs), 21 BL Lacs, 13 FRI and 12 FRII radio galaxies to study the jet power and broadline luminosity relation, and the jet power and black hole mass relation. Furthermore, we obtain the histograms of key parameters. Our main results are as the follows:(i) We found that the FSRQs are roughly separated from BL Lacs by the Ledlow-Owen FRI/FRII dividing line in the log P jet − log M plane. This result supports the unification model that BL Lacs unify with FRI radio galaxies and FSRQs unify with FRII radio galaxies.(ii)We found that the coefficient of the best-fit linear regression equation of log L BLR − log P jet relation is very close to 1 for our sample. The correlation between broad line luminosity and jet power is significant which supports that jet power has a close link with accretion.

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Section: Conclusion and Discussionsupporting

confidence: 71%

Section: The Sample Of Blazarsmentioning

confidence: 99%

Section: The Sample Of Blazarsmentioning

confidence: 99%

mentioning

confidence: 99%

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Jet/accretion and unification for FSRQs/FRII and BL Lac objects/FRI radio galaxies

Chen

Zhang

et al. 2015

Astrophys Space Sci

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“…If there is significant release of mechanical energy, the true efficiency might be higher. For instance, in M87 the kinetic energy carried away by the jet is much larger than the radiated one (Owen, Eilek, & Kassim 2000) and, in general, the jets of radio loud AGN's can carry away up to half of the total power in kinetic energy (Rawlings & Saunders 1991;Celotti, Padovani, & Ghisellini 1997;Tavecchio et al 2000). The release of mechanical and radiative energy is important for the feedback on the galaxy which is thought to be one of the causes behind the MBH-σ⋆ and MBH-L bul correlations (e.g.…”

Section: Accretion Efficiency and Eddington Ratiomentioning

confidence: 99%

Local Supermassive Black Holes, Relics of Active Galactic Nuclei and the X-ray background

Marconi

Risaliti

Gilli

et al. 2005

Growing Black Holes: Accretion in a Cosmological Context

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We quantify the importance of mass accretion during AGN phases in the growth of supermassive black holes (BH) by comparing the mass function of black holes in the local universe with that expected from AGN relics, which are black holes grown entirely with mass accretion during AGN phases. The local BH mass function (BHMF) is estimated by applying the well-known correlations between BH mass, bulge luminosity and stellar velocity dispersion to galaxy luminosity and velocity functions. We find that different correlations provide the same BHMF only if they have the same intrinsic dispersion. The density of supermassive black holes in the local universe which we estimate is ρ BH = 4.6 +1.9 −1.4 h 2 0.7 × 10 5 M ⊙ Mpc −3 . The relic BHMF is derived from the continuity equation with the only assumption that AGN activity is due to accretion onto massive BH's and that merging is not important. We find that the relic BHMF at z = 0 is generated mainly at z < 3 where the major part of BH's growth takes place. Moreover, the BH growth is anti-hierarchical in the sense that smaller BH's (M BH < 10 7 M ⊙ ) grow at lower redshifts (z < 1) with respect to more massive one's (z ∼ 1 − 3). Unlike previous work, we find that the BHMF of AGN relics is perfectly consistent with the local BHMF indicating the local black holes were mainly grown during AGN activity. This agreement is obtained while satisfying, at the same time, the constraints imposed from the X-ray background. The comparison between the local and relic BHMF's also suggests that the merging process is not important in shaping the relic BHMF, at least at low redshifts (z < 3), and allows us to estimate the average radiative efficiency (ε), the ratio between emitted and Eddington luminosity (λ) and the average lifetime of active BH's. Our analysis thus suggests the following scenario: local black holes grew during AGN phases in which accreting matter was converted into radiation with efficiencies ε = 0.04 − 0.16 and emitted at a fraction λ = 0.1 − 1.7 of the Eddington luminosity. The average total lifetime of these active phases ranges from ≃ 4.5 × 10 8 yr for M BH < 10 8 M ⊙ to ≃ 1.5 × 10 8 yr for M BH > 10 9 M ⊙ but can become as large as ∼ 10 9 yr for the lowest acceptable ǫ and λ values.

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