Recent Highlights from the Fermi-LAT Benoît Lott CEN Bordeaux-Gradignan lott@cenbg.in2p3.fr on behalf of the Fermi-LAT collaboration

LAT performance energy range: 30 MeV - 300 GeV large FOV: 2.4 sr http://www-glast.slac.stanford.edu/software/IS/glast_lat_performance.htm energy range: 30 MeV - 300 GeV large FOV: 2.4 sr Aeff:~8000 cm2 at 1 GeV PSF: q68%~0.8° at 1 GeV altitude: 565 km inclination: 25.6° orbital period: 91 min whole sky covered in 2 orbits in survey mode (rocking angle 50°) public data, available within 12 h Pass 8 data released soon operation garanteed until 2018

3FGL (arXiv:1501.02003) Acero et al. (2015, in press) • 4 years, P7REP_SOURCE_V15, improved PSF • Front/Back handled separately (different isotropic and Earth limb) • Energy range 100 MeV - 300 GeV 3033 sources (2192 at |b|>10°) >4.1 s

Data Interval (months) LAT Source Catalogs Catalog Energy Range (GeV) Data Interval (months) Sources Event Selection Release Date 0FGL 0.2-100 3 205 P6V1 DIFFUSE Feb. 2009 1FGL 0.1-100 11 1451 P6V3 DIFFUSE Feb. 2010 2FGL 24 1873 P7V6 SOURCE Aug. 2011 1FHL 10-500 36 511 CLEAN Jun. 2013 3FGL 0.1-300 48 3033 P7V15 Jan. 2015 The catalogs are analyses over successively deeper data sets, and also represent successive analysis refinements, from event classification on up

Associated Source Classes Blazars and pulsars dominate Briefer transient classes of LAT sources (GRBs, solar flares) are not represented at all* The fraction of unassociated sources is about 1/3 This has not decreased appreciably as the FGL catalogs have deepened and counterpart catalogs have grown * This is by design; time intervals of the brightest flares were excluded from the analysis

The Third LAT AGN catalog (3LAC) Ackermann M. et al., arXiv:1501.06054 48 month data set 2192 TS>25, |b|>10° sources 3LAC: 1591 counterparts 1563 sources 1444 AGNs in Clean Sample (no dup., no flags) Census : 415 FSRQs 602 BLLacs (~50% with measured z) 162 LSPs, 178 ISPs, 272 HSPs, 20 no class. 413 of unknown type (BCUs) 23 other AGNs Differences between Northern and Southern Hemispheres: 40% of BL Lacs in Southern Hemisphere Preliminary

Second Fermi Hard-Source List (2FHL) 6 years of Pass8 data at E > 50 GeV increase in Aeff of 25%, in PSF of 20% at 50GeV (50% at 500GeV) 51,000 photons E> 50 GeV ~ 1 ph /deg 2 (EGRET: 1500 ph E>10 GeV) 18,000 photons E>100 GeV 2,000 photons E>500 GeV Fills the gap between Cherenkov ground-based observations and GeV all sky survey Preliminary

Second Fermi Hard-Source List (2FHL) Preliminary Detections 320 sources 71 detected by ACTs (TeVCat) 249 not detected by ACTs 206 in 1FHL 60 new sources Only 10 FSRQs BL Lacs have softer spectra than in 3FGL (0.1-300 GeV) and 1FHL (10-500 GeV) Should be a valuable resource to establish pointing strategies for existing ground-based Cherenkov telescopes and CTA.

Dark-matter search: Line-like feature near 133 GeV Spheroidal dwarfs, galaxy clusters, Galactic center Hint of a signal for a while but feature too narrow and also present in Earth limb P8_CLEAN R3 5.8 yr ArXiv 1506.00013, PRD in press

Galactic Center data-model Claims of a potential signal of dark matter annihilation from this region Set of models for the diffuse emission in the inner 15°x15° of the Milky Way, by fitting GALPROP-derived templates plus point sources. Foreground/background emission, excluding the 15°x15° region, assessed from all-sky data (CR source distribution, gas intensity and spectral index, and IC intensity across galactocentric rings) IC emission from inner kpc is higher than predicted and is the dominant interstellar emission component in this region (combination of ISRF and CR leptons) Enhancement approximately centered the Galactic center with a spectrum that peaks in the GeV range, persisting across all models . Spectral properties vary widely with the modelled interstellar emission. Foreground/background accounts for most of the emission. Its determination is crucial in extracting the contribution from the Galactic center region. data-model

LMC: PSR J0540-6919 First «extragalactic» gamma-ray pulsar ! In Large Magellanic Cloud Power law with exp. cutoff spectrum • Pulsation search using photon weighting based on model • Ephemeris from RXTE over 3.5 yrs • Pulsations at 6.8σ (facilitated by Pass 8) • The Crab twin, giant spin-down power • Rare extreme case useful to test emission models Gamma-ray luminosity 6.3 1036 erg/s ~10 times more luminous than Crab (also more luminous in pulsed X-rays)

PG 1553+113 HSP BL Lac 0.395 < z < 0.62 one of the brightest BL Lacs in the X-ray band TeV source (HESS, MAGIC) Indication for a periodic behavior in the radio (15 GHz) the optical (R-band) the LAT band Autocorrelation gives a peak at 750 days Interpretation: binary black hole? warped disk? other?

Shortest timescales PKS 1509-089 3C 454.3 model data Tr=300 s +700 -300 Preliminary Constraints on size and location of emitting zone 4 sources show Tmin close to 3 hr: 3C 454.3, 3C 273, 4C+21.35, PKS 1510-089 RS/c~104 M9 s Binned light curves unsuitable to derive Tmin accurately Unbinned maximum-likelihood method Sub-hour variability (<20 min) is found for 3C454.3 and PKS 1510-089 3C 454.3 3hr exposure rate model data + 3hr + 6hr   Tr<1000 s

Conclusions The Fermi-LAT has revolutionized our knowledge of the gamma-ray sky, regarding both galactic and extragalactic sources. The 4FGL is already in the works. Operation will continue at least till 2018. The data reprocessed with the new Pass 8 event selection/data reconstruction scheme open up new perspectives. They should be released within a few weeks.