The Radiative Efficiency of Individual AGN. Shane Davis ( IAS ) & Ari Laor ( Technion ). Why is the radiative efficiency ( η ) important?. Gives the spin (a * ), which indicates the accretion history a * =1 → uniform accretion geometry a * =0 → independent accretion events
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The Radiative Efficiency of Individual AGN Shane Davis (IAS) & Ari Laor (Technion)
Why is the radiative efficiency (η) important? Gives the spin (a*), which indicates the accretion history a*=1 → uniform accretion geometry a*=0 → independent accretion events How much mechanical power can go to wind/jet? What is the disk structure? (is it radiatively efficient, or advection, radiation trapping take place?)
Measuring the Radiative Efficiency (η) The Soltan argument - ηav/(1- ηav) = total L/ total MBH → ηav≥0.1(e.g. Yu & Tremaine 2002; Elvis et al. 2002; Marconit al. 2004; Barger et al. 2005) Can also estimate ηav(z) and ηav(L), but with a larger uncertainty In individual AGN Lbol= η × Mdotc2 Can we measure Mdot directly?
For a local BB accretion disk, Newtonian gravity, no edge effects: Does it works for a relativistic accretion disk (Novikov & Thorne)? Using an atmospheric model (Hubeny’s TLUSTY)? Using relativistic radiation transfer (Agol’s KERTRANS)? Using different black hole spin (a*)? Using different values of α?
Fixed Mdot = changing MBH and a* 0.998 0.9 a*=0 a*=0 0.9 0.998 If MBH is known, Mdot is fixed by Lν, Mdot independent of a*
Atmospheric models – BB versus TLUSTY Optical A small effect in the optically emitting region
Derived Mdot for 80 PG Quasars Ratio of Mdot for different a* and atmospheric models
The Results for the 80 Quasars BLR σ What is Lbol fot the PGs? need it for η=Lbol/Mdotc2
Combine Optical, UV (HST+ FUSE), X-Ray (ROSAT) + extrapolations
The dependence of η on MBH log(η)= -1 ± 0.3 a*=0.998 a*=0
Ifη implies a* Fanidakis et al. arXiv:0911.1128
But why is the SED universal? Are we missing something fundamental about AD SED?
Conclusions η is correlated with MBH a* is related to MBH , but maybe very low η due to wind/radiation trapping? very high η due to what? What drives the universal SED? (just an a* - MBH coincidence?)