Markos Georganopoulos 1,2 David Rivas 1,3 1 University of Maryland, Baltimore County 2 NASA Goddard Space Flight Center 3 Johns Hopkins University SUPER-EDDINGTON JETS ARE REQUIRED TO EXPLAIN THE BRIGHTEST BLAZAR FLARES THE CASE OF THE TEV FSRQ 4C (PKS ) SUPER-EDDINGTON JETS ARE REQUIRED TO EXPLAIN THE BRIGHTEST BLAZAR FLARES THE CASE OF THE TEV FSRQ 4C (PKS )

Bolometric flare luminosity assuming isotropy: L iso =3x10 48 erg s -1 (Tanaka et al. 2011) M BH =6x10 8 M , L edd =8x10 46 erg s -1 (Farina et al. 2012) Aleksic et al Ghisellini et al δ=Γ=20, from β app =10-26 (Lister 2010,13)

So, during major flares, the released photons can carry a significant fraction of the Eddington Luminosity. Focus on the most economic jets: no hadrons Q: How much electron jet power do we need to produce that much photon power? A: If we can ‘burn’ the leptons efficiently (fast cooling) we just need Bur if we cannot (slow cooling) we need significantly more power

Q: What determines the cooling regime? A: The blazar location pc, away from all photon fields (from multi- wavelength studies of Marscher’s group). Slow cooling, super-Eddington flaring jet Sub-pc or pc scales. Fast cooling on the UV broad line photons (0.1 pc) or Fast cooling on the IR photons of the molecular Torus (~1 pc). In both cases the jet electron power is sub-Eddington.

Q: Can the flare of PKS take place in the broad line region?

Q: So, can the flare of PKS take place in the molecular torus? Then a sub-Eddington power in leptons would suffice to produce the flare. A: We need to check if a jet that carries only radiating leptons will decelerate due to Compton drag. This was checked by Ghisellini & Tavecchio (2010) for the case of BLR emission and was found to be significant.

Two couple equations describe Compton drag: Analytical solution for monoenergetic electrons with no protons : Comparing our numerical solution to the analytical:

Accretion luminosity: L acc =5x10 46 erg s -1 (Tavecchio et al 2011). Even for L jet =L Edd, the jet decelerate significantly. It takes a 2L Edd jet to avoid significant deceleration How much jet power do we need to avoid significant deceleration?

CONCLUSIONS: 1. Bright blazar flares carry an angle-integrated photon power that can reach a significant fraction of L Edd. 2. If such flares take place in environements without substantial external photon fields, as expected at pc, the cooling is slow and the jet power, even just considering leptons, is super-Eddington. 3. If such flares take place in an environment like the molecular torus or the broad line region, where ample photons permeate the jet, cooling is slow and the lepton power required is equal to the angle-integrated photon power. 4. In this case, however, such a jet containing only leptons will decelerate substantially, contrary to VLBI observations that record highly superluminal motions. 5. To address this issue, a non-leptonic component is required, such that the total jet power becomes equal or higher than the Eddington luminosity. NO MATTER WHERE BRIGHT FLARES OCCUR, THEY REQUIRE SUPER-EDDINGTON JETS