Blazars & GRBs Gabriele Ghisellini INAF-Osservatorio di Brera The fastest macroscopic objects of the Universe
Lister ~10 > 10 Fermi FSRQs
Earlier on: isotropic explosion
Later: energy crisis + collapsar scenario
jet Blazars: collimation 1/ GRBs: collimation GRBs: collimation jet
jet Blazars: collimation 1/ GRBs: collimation GRBs: collimation jet
jet L ~ L’ 4 L ~ L’ ( jet ) 2 Blazars GRBs
0 Molinari+ 2007
0
0 E k,iso n t peak 3 1/8 t peak
Ghirlanda Liang+ 2012
Blazars: the general picture
Torus ~1-10 pc Broad Line Region ~0.2 pc Within R BLR U BLR = const Within R Torus U IR = const R BLR R Torus disk Big blazars L>0.01L Edd
BLR <<0.2 pc weak cooling SSC only “ADAF disk” L<0.01L Edd BL Lacs
R diss FSRQs: emission lines many seed photons BL Lacs: no or weak lines
FSRQs BL Lacs FSRQs R diss FSRQs BL Lacs
FSRQs FSRQsFSRQs
Blazars and GRBs: same efficiency
Collimation corrected Nemmen+ Science 2012 blazars GRBs
Fermi blazars, one p per e- GRBs
Jet launching Internal pressure or magnetic field? or magnetic field?
n o R Jet opacity: blazars n o from M out ~ P jet 1 P jet 1 L Edd Jet opacity: GRBs aT 0 4 kT 0 ~ n + ~ P jet,51 M1M1M1M /23/4
Jet launching In GRBs we have 2 possibilities: - internal pressure: the huge optical depth traps photons inside - magnetic field In blazars: - internal pressure: the optical depth is small - magnetic field
Jet launching In GRBs we have 2 possibilities: - internal pressure: the huge optical depth traps photons inside - magnetic field In blazars: - internal pressure: the optical depth is small - magnetic field Magnetic field: - Produced and amplified by the disk - Link with accretion
Blandford & Znajek U B ~ c R s This explains why P j ~ L d B ~ G in GRBs B ~ 10 4 G in blazars B ~ 10 9 G in galactic superluminals
synchro EC Small B torusdisk X-ray corona
Fermi FSRQs Power in cold protons (1 per emitting e-) Power in rel. electrons Power in Poynting flux Power in radiation (model indipendent) Disk luminosity
M out /M in for blazars and for GRBs P jet = M out c 2 L d = M in c 2 for blazars:
M out /M in for blazars and for GRBs P jet = M out c 2 L d = M in c 2 for blazars: P jet LdLdLdLd M out M in = ~ blazars
M out /M in for blazars and for GRBs P jet = M out c 2 L d = M in c 2 for blazars: for GRBs: M in ~ 0.1 M O t burst P jet LdLdLdLd M out M in = M out M in = c M O EkEkEkEk ~ 5.5x10 -4 2222 E k52 ~ blazars
Blazars and GRBs: a difference
Blazars: the redder the more powerful cooling GRBs: the bluer the more powerful heating?? ? “Amati” “Ghirlanda” E peak [keV] E [erg]
Conclusions Jets are the most efficient engine of Nature Compare jet power and L disk as a function of the accretion rate. Normalize to Eddington.
? Late prompt in GRBs?
blazars GBRs
Fossati et al. 1998; Donato et al The “blazar sequence” FSRQs BL Lacs BATIntegral
FSRQs Line strength Fossati et al. 1998; Donato et al. 2001
FSRQs BL Lacs M/M Edd Fossati et al. 1998; Donato et al Next talk by Meyer
Sbarrato SDSS+1LAC Do we really need to divide blazars? 5x10 -4 EW<5A EW>5A Narayan & Yi 1995: L BLR /L Edd ~ Sharma+ 2007: L BLR /L Edd ~ M- Plotkin+ 2011
Black hole masses (for FSRQs)
UVOT XRT Fermi GG, Tavecchio & Ghirlanda 2009 Low energy synchro peak: leave the disk naked! torus disk X-ray corona synchro SSC EC M BH =2x10 9
BAT M BH =10 10
The jet cannot have less power than what required to produce the observed luminosity: P jet L obs 2222 > If P jet is twice as much, halves. We can take that as the minimum P jet. This limit is model-independent.
1 proton per electron no pairs Having pairs would reduce P jet. But where are they created?
Pause P jet ~ Mc 2, even larger than L dP jet ~ Mc 2, even larger than L d For all M/M EddFor all M/M Edd BL Lacs ADAF FSRQs SSBL Lacs ADAF FSRQs SS L BLR /L Edd divides BL Lacs from FSRQsL BLR /L Edd divides BL Lacs from FSRQs Matter, not magnetic, dominatedMatter, not magnetic, dominated
P r = radiation ~ L obs / 2 P e = relat. electrons P p = protons P B = B-field R jet power and accretion luminosity ~10 17 cm Shakura-Sunjaev disk: L d P jet = P e +P p +P B
What is a blazar? A jetted AGN, whose jet is relativistic ( ~10) and is “pointing at us”. A jetted AGN, whose jet is relativistic ( ~10) and is “pointing at us”. To be more quantitative: To be more quantitative: view For each blazar, 2 2 radio-loud AGN pointing elsewhere: FR I and FRII radio- galaxies
3 months, 10 BL Lacs Flat Steep FSRQs LLLL Fossati et al. 1998; Donato et al. 2001
M/ M Edd GG, Maraschi, Tavecchio years– 4 Ackermann+ 2011
Molinari+ 2007
Isotropic Collimation corrected