Moriond 04/02/09Benoit Lott New insight into Gamma-ray Blazars from the Fermi-LAT Benoît Lott CEN Bordeaux-Gradignan on behalf of the Fermi-LAT collaboration

Moriond 04/02/09Benoit Lott Fermi-LAT as an all-sky monitor OR103 FSRQ z=1.83 ATEL #1650 S.Ciprini et al.

Moriond 04/02/09Benoit Lott 3-month sky survey TS=100, photon index=2.2 Flux(E>100 MeV) ph cm -2 s -1

Moriond 04/02/09Benoit Lott Two flavors of blazars: FSRQs and BLLacs Defining property: strong emission lines intense radiation field (disk, clouds) outside the jet High power (~ erg/s) Parent population: FRII Low synchrotron peak (IR) in SED 46 FSRQs in EGRET all-sky survey (18 months) high redshift 0.1 < z < 2.3

Moriond 04/02/09Benoit Lott Two flavors of blazars: FSRQs and BLLacs from the “BL Lacerta” archetype Defining property: nearly lineless Low ambient radiation field “Low” power (~ erg/s) Parent population: FR I Low peak (Opt/IR): LBL High peak (UV/X-rays): HBL (TeV) 14 BLLacs in EGRET all-sky survey Low redshift 0< z < 0.9

Moriond 04/02/09Benoit Lott BZCat (Massaro et al. 08) Compilation of 2500 known blazars association based on spatial coincidence (Mattox et al., 01) 102 high-conf. (P>90%) associations 4 low-conf. (40%<P<90%) associations CGRaBS (Healey et al. 08) 1627 radio sources from CRATES association based on Figure-of-Merit (spatial, radio and X spectrum) established from EGRET 101 high-conf. (P>90%) associations 14 low-conf. (40%<P<90%) associations 0FGL: 132 sources with TS>100, |b|>10° 7 pulsars, 125 AGN candidates associations celestialgalactic

Moriond 04/02/09Benoit Lott LAT Bright AGN Sample (LBAS) 125 non-pulsar sources at |b|>10° 106 high-confidence (P>90%) associations with AGNs: (LBAS) 10 lower-confidence associations FSRQs: 57 BLLacs: 42 Uncertain class: 5 Radiogalaxies: Cen A, NGC % BLLacs (23% for EGRET) 7 HBLs (3+1 for EGRET) 9 unidentified (3EG: 96/181 at |b|>10°) Preliminary 57 FSRQ 42 BLLac 6 of Uncertain class 2 Radio Galaxies  95% ~0.14° (EGRET sample ~0.62°)

Moriond 04/02/09Benoit Lott Flux vs index FSRQ BLLac Uncertain Radio Galaxies TS=100 b=20, 80 deg. TS=100 b= 20 deg. E< 3 GeV Preliminary

Moriond 04/02/09Benoit Lott Fermi EGRET EGRET mean flux « 1234 VP» EGRET peak flux: maximum in 2-w VPs Fermi mean flux: 3-m averaged Fermi peak flux: maximum in 1-w periods mean flux weekly peak flux mean vs peak flux peak/mean flux ratio Flux distributions Preliminary

Moriond 04/02/09Benoit Lott 3C454.3 (FSRQ) AO (Int. BL) Mkn501 (HBL) SED at LAT energies Preliminary Significant departures from pure power-law distributions for bright blazars!

Moriond 04/02/09Benoit Lott Photon index distributions Preliminary all BL Lacs FSRQs = 2.33±0.01 =1.99±0.01 Photon index Number of sources FSRQs F BLLacs

Moriond 04/02/09Benoit Lott EGRET vs FERMI photon index FSRQ BLLac Uncertain Radio galaxies 33 AGNs/116 LAT-sources (30%) in 3EG catalog with a comparable flux → duty cycle Others are found at lower fluxes FSRQs: 20 BLLacs: 11 Uncertain: 3 Radio galaxy:1 Preliminary LBAS Sources in 3EG

Moriond 04/02/09Benoit Lott Mukherjee et al Redshift distributions Preliminary EGRET FSRQ BLLac Uncertain Radio galaxies Preliminary FSRQs BZCat LAT BL Lacs BZCat LAT

Moriond 04/02/09Benoit Lott Preliminary Blazar class slope All2.50±0.12 FSRQs2.55 ±0.12 BLLacs2.32 ±0.15 « sky coverage » enables the log N-LogS to be computed Euclidian space: slope=2.5 Preliminary Log N - Log S FSRQs BL Lacs Marco Ajello

Moriond 04/02/09Benoit Lott Luminosity vs redshift Preliminary FSRQ BLLac Uncertain Radio galaxies

Moriond 04/02/09Benoit Lott Preliminary : ratio between the comoving volume within which the source was detected and the maximum volume available for its detection Population uniformly distributed in Euclidian space, non evolving: ~ 0.5 test Sample#objects FSRQs ±0.043 BLLacs ±0.046 All with z> ±0.031 Positive evolution for FSRQs (more FSRQs in the past) Compatible with no evolution for BLLacs

Moriond 04/02/09Benoit Lott Perspectives Luminosity function Contribution of unresolved blazars to Extragalactic Diffuse Background Variability on different timescales Duty cycle of blazars Existence of a blazar sequence ? (evolutionary link between FSRQs and BLLacs?) Gamma-ray radio connection …