Cosmological Evolution of Blazars: new findings from the Swift/BAT and Fermi/LAT surveys M. Ajello [KIPAC/SLAC] L. Costamante, R. Sambruna, N. Gehrels, J. Greiner, J. Tueller, J. Chiang, A. Escala, R. Mushotzky, A. Rau, J. Wall + On behalf of Fermi/LAT collaboration

M. Ajello2 Instruments Swift-BAT Band: keV FoV: 1.4 sr Monitor: 70% sky/day Pos. res.: 1’-5’ Fermi-LAT Band: GeV FoV: 2.4 sr Monitor: 100% sky/3hr Pos. res.: 3’-21’

M. Ajello3 Why to study blazars at high-E ? Ajello+, 2008, ApJ, 689, hard -rays - Blazars are ~15% of extraG. sources - Evolution of blazars unknown -MeV background unexplained (see Inoue+08 and ref.  -rays - Blazars are >85% of extraG. sources - Evolution of blazars studied with EGRET: low numbers -GeV background ? (see Chiang+98,Dermer+05,Narumoto+06)

M. Ajello4 Ghisellini+99 Tagliaferri+00 Pian+98 PKS IBL HBL FSRQ FSRQs and IBL/LBL ‘peak’ in the MeV band

M. Ajello5 The BAT 3yr Sample 38 blazars (26 FSRQs, 12 BL Lacs) detected up to z~4 9 FSRQs and 3 BL Lacs in common with EGRET/LAT No blazars at low L X and low redshift Ajello+09,ApJ 699, 603 Seyferts blazars

M. Ajello6 Test of Evolution Luminosity function needed to assess the contribution of a source class to the diffuse background Seyferts Blazars 1.Blazars evolve positively at ~3  2.No significant difference between the 2 sub-classes 3. Seyferts ‘do not’ evolve

M. Ajello7 Parametric XLF Luminosity Evolution i.e. objects were more luminous in the past L x (z)=(1+z) k L x Density Evolution i.e. objects were more numerous in the past  (L,z)=  (L,0) (1+z) k Method Maximize Likelihood function based on the product of Poisson prob. of observing 0 or 1 blazars in a dL x dz element: (Marshall+83, Borgani+01, Wall+05)

M. Ajello8 Best-fit XLF for entire population Best Fit Model: PLE with a redshift cutoff coupled to a local double power law XLF Parameters:  1 =-0.87  1.31 <--beaming?  2 = 2.73  0.38 k= 3.45  0.44  =-0.25  0.07 <--3  (Urry&Schafer84)

M. Ajello9 Separating the populations FSRQs (26)BL Lacs (12) Best fit model: PLE: k=3.67,  =-0.30 Local XLF slope: 2.49 ±0.37 Best fit model: PLE: k=-0.8±2.4 !! Local XLF slope: 2.61 ±0.36 Claim of negative (Rector+00, Beckmann+03) or no (Caccianiga+02, Padovani+07) evolution not confirmed/denied BL Lacs ‘produce’ <1% CXB

M. Ajello10 The MeV Background FSRQs RQ AGN, from Gilli+07 Watanabe+09 Blazars produce: –10% of 2-10 keV –20% of keV –~100% 1 MeV FSRQs detected by BAT must peak at ‘MeV’ energy not to violate CXB constraint EGRET did not detect high- z BAT blazars. According to Zhang+05, Sambruna+07, Tavecchio+07, Watanabe+09 they are MeV blazars FSRQs RQ AGN, from Gilli+07

M. Ajello11 The LAT view of blazars FSRQ BL Lac Radio Galaxy Uncertain (Abdo et al. 2009, ApJ 700, 597) Aug/Sep/Oct high confidence list: 205 sources with >10  detection 132 with |b| > 10  (7 pulsars, 14 unid) –111/125 are bright, flat spectrum radio sources –98/111 have optical classifications, 89/111 have redshifts

M. Ajello12 Some Key Properties F FSRQs F BLLacs BAT LAT

M. Ajello13 Blazar Evolution in LAT FSRQs (59)BL Lacs (29) Strong Positive Evolution V/V m =0.645  Power-law slopes: ~2.5 No significant Evolution V/V m =0.422  But: 13/42 BL have no z Power-law slopes: ~2.2

M. Ajello14 Anti-hierarchical growth Larger structures comes first: tracing the merging history of spheroids (eg. Franceschini+99) The bulk of super- massive BHs is formed at z~1 : tracing the SFR of galaxies (eg. Madau+99) Beaming allows to study AGNs at large z Hasinger+05

M. Ajello15 Hasinger+05 Galaxy-AGN co-evolution SMBHs and galaxies co- evolve through the history of the Universe –M BH -  relation (e.g.Merrit&Ferrarese01) –Co-evolution of SFR and AGN (e.g. Madau99, Hasinger+05)

M. Ajello16 AGN-Cluster Interaction AGNs inflates cavities in the ICM Total non-thermal pressure in the atmospheres of giant E gal is ~10% (Churazov+09) Turbulent pressure <5% (Werner+09) AGN activity regulates the thermal state of the gas by injecting energy in the ICM Abdo+, ApJ 699, 31 CR pressure <15% (Keith’s talk)

M. Ajello17 Conclusions Blazars in BAT are 15% of total AGN population –Strong evolution (PLE) with evidence for a redshift peak –They account for ~100% of the MeV background Blazars in LAT are the main population: –FSRQs evolve strongly, evolution is complex –BL Lacs seem not to evolve….but wait for a larger sample

M. Ajello18 Paucity of blazars at low L X : beaming effect ? Urry & Shafer+84 Beaming alters the intrinsic luminosity function ->  (L)dL = P(L| L )  ( L )d L where L=  p L

M. Ajello19 FSRQs RQ AGN, from Gilli+07 Previous attempts Comastri+06 Giommi+07 Required to produce ~10% of CXB at 1 keV and not exceed the CXB at ~MeV Derived from logN-logS of blazar in radio

M. Ajello20 In deep surveys Deep X-ray surveys ‘must’ contain a fraction of blazars Selection of C-thick AGN using hardness ratios becomes dangerous Unless the evolution of RQ and RL AGN is different….. logN- logS [ keV] Courtesy P. Giommi blazars RQ AGN, Hasinger+05 Looking forward to Astro- H/NuSTAR

M. Ajello21 The BAT survey: Deep, all-sky and Unbiased All-sky observed down to ~0.5 mCrab (~6e-12 erg/cm 2 /s) No bias against N H up to Compton-thick regime 2-10 z= z= z=0, z=1 Chandra/XMM much better sensitivity but smaller FOV and biased BAT more sensitive than Suzaku/HXD on long exposures