Antoine Letessier Selvon (CNRS/UPMC) FRIF days Dourdan January 2014!1 ULTRA HIGH ENERGY COSMIC RAYS WHERE DO WE STAND AFTER YEARS AT THE PIERRE AUGER OBSERVATORY
Antoine Letessier Selvon (CNRS/UPMC) FRIF days Dourdan January 2014!2 THE WORLD S LARGEST COSMIC RAY OBSERVATORY Collaboration : ~ 500 members & 19 countries! Argentina Australia Brazil Croatia Czech Republic France Germany Italy Mexico Netherlands Poland Portugal Slovenia Spain United Kingdom USA Bolivia* Romania* Vietnam* *Associated Pierre Auger! Observatory Full members Associate members
SELECTED NEWS AND RESULTS OBSERVATORY PERFORMANCE" Exposure ~ 40 000 km 2 sr yr (+50% since Beijing)! Status of the observatory & monitoring! ENERGY SPECTRUM" New energy scale (+16%@1EeV / +12%@ EeV)! Updated energy spectrum from 3x 17 ev! PHOTONS AND GAMMA FLUXES" MASS COMPOSITION" Updated X max data! Confrontation to model predictions! HADRONIC INTERACTIONS" Muon number! Direct counting (AMIGA Infill)! ANISOTROPY STUDIES" Large scales (EeV)! Sources (> 50 EeV) VCV Antoine Letessier Selvon (CNRS/UPMC) FRIF January 2014!3
Antoine Letessier Selvon (CNRS/UPMC) FRIF days Dourdan January 2014!4 DETECTION PRINCIPLES
Antoine Letessier Selvon (CNRS/UPMC) FRIF days Dourdan January 2014!5 STATUS & PERFORMANCE
Antoine Letessier Selvon (CNRS/UPMC) FRIF days Dourdan January 2014!6 STATUS & PERFORMANCE The world s largest cosmic ray observatory! In operation since 2004 INFILL/AMIGA
STATUS & PERFORMANCE THE HYBRID The world s largest cosmic ray observatory Pierre Auger 24+3 Telescopes, 4+1 sites Observatory CONCEPT ALLOWS FOR A DATA-DRIVEN CALIBRATION OF THE ~0% DUTY CYCLE 1660 Water Cherenkov Tanks, 3000 km2 SURFACE ARRAY USING THE CALORIMETRIC INFORMATION FROM THE FLUORESCENCE TELESCOPES Antoine Letessier Selvon (CNRS/UPMC)!7 FRIF days Dourdan January 2014
STATUS & PERFORMANCE 40 000 km 2 sr yr / about an additional 6 500 km 2 sr each year 82318 events 174 events 11155 events 29585 events Two arrays, zenith angle aperture up to 80º SD energy (angular) resolution < 12% (< 1º) above EeV Antoine Letessier Selvon (CNRS/UPMC) FRIF days Dourdan January 2014!8
Antoine Letessier Selvon (CNRS/UPMC) FRIF days Dourdan January 2014!9 ENERGY SCALE & ENERGY SPECTRUM
Antoine Letessier Selvon (CNRS/UPMC) FRIF days Dourdan January 2014! ENERGY SCALE Telescope optical properties Joint Auger/TA effort to conduct! a common calibration campaign To study the optics of the telescope in more detail, telescope components like the mirror, the camera, the corrector lens or the filter have been manipulated (e.g. cleaned), covered orremoved.
ENERGY SCALE The fluorescence yield 1 EeV EeV The atmosphere The absolute calibration! of the telescopes Reconstruction of the longitudinal! profile of the showers The invisible energy!11 Antoine Letessier Selvon (CNRS/UPMC) FRIF days Dourdan January 2014
Antoine Letessier Selvon (CNRS/UPMC)!12 FRIF days Dourdan January 2014 4 DISTINCT DATA SETS Regular 1500m grid SD [0º-60º] zenith; 3 EeV (80k)!! Inclined 1500m grid SD [62º-80º] zenith; 4 EeV (11k)!! Infill 750m grid SD [0-60)] zenith; 0.3 EeV (30k)!! Hybrid [0-60º] zenith; 1 EeV (11k)
Antoine Letessier Selvon (CNRS/UPMC) FRIF days Dourdan January 2014!13 AUGER ENERGY SPECTRA
THE AUGER ALL-PARTICLE FLUX Auger 2013 preliminary hev 2 km 2 sr 1 yr 1i 38 37 358 6317 3656 2201 1295 3242 2627 2015 14 52202 29684 21413 13014 8624 5807 3984 2700 1701 1116 676 427 188 90 Ankle 45 7 Cut-off 3 1 E 3 J(E) Normalizations: Hybrid -6%, Inclined +4%, 750 m array +2%, SD -1% 130 000 events! 36 17.5 18.0 18.5 19.0 19.5 20.0 20.5 log (E/eV) Antoine Letessier Selvon (CNRS/UPMC) FRIF days Dourdan January 2014
THE AUGER ALL-PARTICLE FLUX Auger 2013 preliminary hev 2 km 2 sr 1 yr 1i 38 37 358 6317 3656 2201 1295 3242 2627 2015 14 52202 29684 21413 13014 8624 5807 3984 2700 1701 1116 676 427 188 90 γ 1 = 3.3 log (E ankle /ev) = 18.7 log (E 1/2 /ev) = 19.7 E 3 J(E) 45 γ 2 = 2.6 7 3 1 36 17.5 18.0 18.5 19.0 19.5 20.0 20.5 log (E/eV) Antoine Letessier Selvon (CNRS/UPMC) FRIF days Dourdan January 2014
Antoine Letessier Selvon (CNRS/UPMC)!16 FRIF days Dourdan January 2014 E [ev] 18 19 20 Auger 2013 preliminary E [ev] 18 19 20 E 3 J(E) ev 2 km 2 sr 1 yr 1 38 37 358 6317 3656 2201 1295 3242 2627 2015 14 52202 29684 21413 13014 8624 5807 3984 2700 1701 1116 676 427 188 90 36 17.5 18.0 18.5 19.0 19.5 20.0 20.5 log (E/eV) 45 7 3 1 E 3 J(E) ev 2 km 2 sr 1 yr 1 38 37 36 Proton, E cut = 20 ev Proton, E cut = 20.5 ev Iron, E cut = 20 ev Iron, E cut = 20.5 ev E/E = 14 % 17.5 18.0 18.5 19.0 19.5 20.0 20.5 log (E/eV) Ideal scenarios of homogeneously distributed sources dn/de ~ E -β, cosmic evolution (1+z) m! m=5 (0), β=2.35 (2.3) proton (iron)
Antoine Letessier Selvon (CNRS/UPMC) FRIF days Dourdan January 2014!17 PHOTONS AND NEUTRINOS? y -1 ] -2 sr -1 [km 0 Integral Flux E>E 1-1 -2 Y Hyb 2011 Hyb 2009 Y upper limits 95% C.L. A TA SD A SHDM SHDM' TD Z-burst GZK s -1 sr -1 ] -2 dn/de [ GeV cm 2 Single flavour (90% CL) E -4-5 -6-7 -8 ν limits IceCube-40 (333.5 days) Auger 2012 (6 yr) ANITA-II (28.5 days) RICE 12 (4.8 yr) HiRes PRELIMINARY Exotic scenarios Z-burst (Kalashev) TD (Sigl) -3 18 19 20 Energy[eV] ν e -9 : ν µ : ν τ = 1 : 1 : 1 17 18 E ν [ev] 19 20 21 Current Auger limits rule out top-down models as dominant production of UHECR
Antoine Letessier Selvon (CNRS/UPMC) FRIF days Dourdan January 2014!18 DEPTH OF SHOWER MAXIMUM & MASS COMPOSITION
Antoine Letessier Selvon (CNRS/UPMC)!19 FRIF days Dourdan January 2014 <X max> and σ(x max ) data Auger 2013 preliminary Auger 2013 preliminary ] 2 X max [g/cm 850 800 EPOS-LHC QGSJetII-04 Sibyll2.1 proton ] 2 ) [g/cm max σ(x 70 60 50 proton 750 700 650 67 39 132 43 438 249 1486 857 96 334 177 606 2498 1175 3520 2043 2952 3864 iron 40 30 20 iron 18 19 20 E [ev] 0 18 19 20 E [ev] Xmax : Dominantly light around 3 EeV, getting heavier above! Supported by the decreasing fluctuations (right)
MASS COMPOSITION From <X max> and σ(x max ) to <lna> and σ(lna) σ 2 (ln A) <ln A> minimum @ ankle! (dispersion highest)!! <lna> < 2 for all models! (intermediate masses).!! σ 2 lna is small ~ 1! (vicinity mix) <lna> = 0 for proton and 4 for iron " σ 2 (lna) = 0 for a pure composition and 4 for a 50-50 mix p-fe Antoine Letessier Selvon (CNRS/UPMC) FRIF days Dourdan January 2014!20
Antoine Letessier Selvon (CNRS/UPMC) FRIF days Dourdan January 2014!21 MASS COMPOSITION II Muon Production Depth distribution (MPD) in a nutshell l = p r 2 +(z ) 2 Measured Obtained
Antoine Letessier Selvon (CNRS/UPMC) FRIF days Dourdan January 2014!22 MASS COMPOSITION II MPD in a nutshell Decent resolution & no bias Indep. from X max and higher E 70 g/cm2
Events 300 200 0 18.1 > log(e) > 18.0 1407 events Events 200 150 0 50 18.2 > log(e) > 18.1 1251 events Events 150 0 50 18.3 > log(e) > 18.2 998 events 0 600 800 00 [g/cm X max 2 ] 0 600 800 00 [g/cm X max 2 ] 0 600 800 00 [g/cm X max 2 ] Events 150 18.4 > log(e) > 18.3 18.5 > log(e) > 18.4 0 18.6 > log(e) > 18.5 781 events 619 events 457 events 0 USING THE FULL 50 50 0 50 Events Events 0 DEPTH OF SHOWER 0 0 600 800 00 2 2 X max [g/cm ] X max [g/cm ] X max 600 800 00 600 800 00 [g/cm 2 ] Events 60 40 20 MAXIMUM 60 18.7 > log(e) > 18.6 18.8 > log(e) > 18.7 331 events 230 events Events 40 40 DISTRIBUTIONS 20 20 Events 18.9 > log(e) > 18.8 188 events 0 600 800 00 [g/cm X max 2 ] 0 600 800 00 [g/cm X max 2 ] 0 600 800 00 [g/cm X max 2 ] Events 40 30 20 19.0 > log(e) > 18.9 143 events Events 40 20 19.2 > log(e) > 19.0 186 events Events 40 19.4 > log(e) > 19.2 30 20 6 events 0 0 0 600 800 00 600 800 00 600 800 00 2 2 2 Antoine Letessier Selvon (CNRS/UPMC) X max [g/cm ] X max [g/cm ] FRIF X max days [g/cmdourdan ] January 2014!23
Antoine Letessier Selvon (CNRS/UPMC)!24 FRIF days Dourdan January 2014 Fe fraction N fraction He fraction p fraction 1 0.8 0.6 0.4 0.2 0 1 0.8 0.6 0.4 0.2 0 1 0.8 0.6 0.4 0.2 0 1 0.8 0.6 0.4 0.2 0 18 19 20 E [ev] EPOS-LHC QGSJET-04 SIBYLL 2.1 XL M/L S/M XS Evolution of mass fraction as a function of energy! from the adjustment of the Xmax distributions
Antoine Letessier Selvon (CNRS/UPMC) FRIF days Dourdan January 2014!25 HADRONIC INTERACTIONS
Antoine Letessier Selvon (CNRS/UPMC) FRIF days Dourdan January 2014!26 Cross section measurements (Proton-Proton) [mb] inel 1 0 90 80 70 60 50 40 30 Auger 2012 (Glauber) ATLAS 2011 CMS 2011 ALICE 2011 TOTEM 2011 UA5 CDF/E7 3 s [GeV] 4 QGSJet01 QGSJetII.3 SIBYLL2.1 Epos1.99 PYTHIA 6.115 PHOJET 5 R µ Figu p-p Xsec @ 57 TeV c.m.s.! derived from p-air and Glauber approximation
Hadronic/muonic contribution in hybrid events ML fit adjusting EM and Had contribution to S 00 Antoine Letessier Selvon (CNRS/UPMC) FRIF days Dourdan January 2014!27
Antoine Letessier Selvon (CNRS/UPMC)!28 FRIF days Dourdan January 2014 <lna> from MPD & <Xmax> Different rapidity gap distributions Pierog
Antoine Letessier Selvon (CNRS/UPMC)!29 FRIF days Dourdan January 2014 <lna> from MPD & <Xmax> Piero g Different rapidity gap distributions ADDITIONAL DATA ALLOWS MORE DETAILED CONSTRAINTS,! IMPROVES UNDERSTANDING OF HADRONIC INTERACTIONS! AND MODEL DESCRIPTIONS
Antoine Letessier Selvon (CNRS/UPMC) FRIF days Dourdan January 2014!30 ANISOTROPY
Antoine Letessier Selvon (CNRS/UPMC)!31 FRIF days Dourdan January 2014 Large scale first harmonic analyses Data up to December 31st 2012 0 Auger 750 m (East-West) Auger 1500 m (East-West) Auger 1500 m (Rayleigh) 99% CL upper limits (isotropy) Equatorial dipole amplitude -1-2 3 bins with chance probability < 1% -3 0.01 0.1 1 0 Energy [EeV] Extended energy range
Antoine Letessier Selvon (CNRS/UPMC)!32 FRIF days Dourdan January 2014 Large scale first harmonic analyses Data up to December 20 (April 2011) Prescription set New data Prescription status 180 180 (about 18 more month to go) 90 90 Phase [deg] 0 Phase [deg] 0 270 270 Auger 750 m (East-West) Auger 1500 m (East-West) Auger 1500 m (Rayleigh) 180 0.01 0.1 1 0 Energy [EeV] 180 0.01 0.1 1 0 Energy [EeV] Auger 750 m (East-West) Auger 1500 m (East-West) Auger 1500 m (Rayleigh)
Antoine Letessier Selvon (CNRS/UPMC)!33 FRIF days Dourdan January 2014 Large scale analyses Equatorial dipole amplitude 0-1 -2-3 -4 EAS-TOP ICE-CUBE KASCADE Grande AGASA Gal C-G Xgal Auger A Auger amplitude S 14 15 16 17 18 19 Energy [ev] Upper Limit - Dipole Amplitude 1-1 -2 1 Z=1 Z=26 E [EeV] If protons dominate and if of Galactic origin,! anisotropies are remarkably small In this examples we exclude the hypothesis that the light! component of cosmic rays comes from stationary sources densely! distributed in the Galactic disk and emitting in all directions.!
Antoine Letessier Selvon (CNRS/UPMC) FRIF days Dourdan January 2014!34 VCV CORRELATION Time ordered Energy ordered ~30% (e.g. : 80% x 0.21 + 20% x 0.7) Telescope Array Consistent with a subdominent p fraction (<20%) at the highest energies
SUMMARY AUGER PROVIDES A WEALTH OF HIGH QUALITY DATA! WE OBSERVE A COHERENT BEHAVIOR OF OBSERVABLES Auger 2013 preliminary Phase [deg] 180 90 0 hev 2 km 2 sr 1 yr 1i 38 37 358 6317 3656 2201 1295 3242 2627 2015 14 52202 29684 21413 13014 8624 5807 3984 2700 1701 1116 676 427 188 90 45 7 3 1? 270 Auger 750 m (East-West) Auger 1500 m (East-West) Auger 1500 m (Rayleigh) 180 0.01 0.1 1 0 Energy [EeV] E 3 J(E) 36 17.5 18.0 18.5 19.0 19.5 20.0 20.5 log (E/eV) 0 Auger 750 m (East-West) Auger 1500 m (East-West) Auger 1500 m (Rayleigh) 99% CL upper limits (isotropy) Equatorial dipole amplitude -1-2 -3 0.01 0.1 1 0 Energy [EeV] Antoine Letessier Selvon (CNRS/UPMC) FRIF days Dourdan January 2014!35
Antoine Letessier Selvon (CNRS/UPMC) FRIF days Dourdan January 2014!36 WHAT TO MAKE OF ALL THIS?
Antoine Letessier Selvon (CNRS/UPMC) FRIF days Dourdan January 2014!37 Classical model for the cut-off The GZK paradigm Cut off is a propagation effect! e-loss by photo pion production Sources are astrophysical objects! distributed like the visible matter, anisotropies Sources are dominantly injecting protons! fermi acceleration with power law spectra (β < -2) Emax at source well above 0 EeV! (GZK)
Antoine Letessier Selvon (CNRS/UPMC) FRIF days Dourdan January 2014!38 Classical model for the cut-off The GZK paradigm Cut off is a propagation effect! e-loss by photo pion production Sources are astrophysical objects! distributed like the visible matter, anisotropies Sources are dominantly injecting protons! fermi acceleration with power law spectra (β < -2) Emax at source well above 0 EeV! (GZK)
Cut-off Maximum Energy scenario 38 37 E 2 km J [ev 3-2 sr -1 yr -1 ] 18 18.5 19 19.5 20 20.5 Proton are extra-galactic at the ankle, 50% from source 50% from prop Antoine Letessier Selvon (CNRS/UPMC) FRIF days Dourdan January 2014!39 log (E/eV) Figure 1.8: Fluxes different mass groups for describing Very heavy in cut-off... Shown are fits based on the maximum-energy scenario (l nario (right panel). The colors for the different mass group
Cut-off Photo disintegration scenario 38 37 E 2 km J [ev 3-2 sr -1 yr -1 ] 18 18.5 19 19.5 20 20.5 Proton only from propagation Antoine Letessier Selvon (CNRS/UPMC) FRIF days Dourdan January 2014!40 log (E/eV) groups for describing the EPOS Auger Intermediate 1.99 spectrum and composition data. mass dominance um-energy scenario (left panel) and the photo-disintegration scehe different mass groups are protons blue, helium gray, nitrogen ] -2 [g cm 70 60 50
Antoine Letessier Selvon (CNRS/UPMC) FRIF days Dourdan January 2014!41 Cut-off sub-dominant p fraction in cut-off PRELIMINAIRE Compatible avec les compatible interprétations with observation
Antoine Letessier Selvon (CNRS/UPMC) FRIF days Dourdan January 2014!42 Classical models for the Ankle Ankle is the proton dip! e-loss of proton by e+/e- production Ankle is source Emax & mass mix! Emax(Z) = Z Emax(p) composition signature [Emax(p) = 4 EeV] Ankle is Galactic to extra-galactic transition! anisotropy signature
Antoine Letessier Selvon (CNRS/UPMC) FRIF days Dourdan January 2014!43 Classical models for the Ankle Ankle is the proton dip! e-loss of proton by e+/e- production Ankle is source Emax & mass mix! Emax(Z) = Z Emax(p) composition signature [Emax(p) = 4 EeV] Ankle is Galactic to extra-galactic transition! anisotropy signature
Before the Ankle Eichler & Pohl, ApJ 742 (2011) 114 Figure 8. A Monte Carlo method, based on analytical solutions to the time-dependent diffusion gure 9. problem, is used to account for intermittency by placing sources at random locations. Assuming a source population that scales with baryon mass density or star formation (e.g., long GRB), we derive constraints arising from intermittency and the observational limits on the composition and anisotropy. It is shown that the composition and anisotropy at 18 ev are difficult to reproduce and require that either (1) the particle mean free path is much smaller than a gyroradius, implying the escape time is very long, (2) the composition is heavier than suggested by recent Auger data, (3) the ultra-highenergy sub-ankle component is mostly extragalactic, or (4) we are living in a rare lull in the UHECR production, and the current UHECR intensity is far below the Galactic time average. Antoine Letessier Selvon (CNRS/UPMC) FRIF days Dourdan January 2014!44
Antoine Letessier Selvon (CNRS/UPMC) FRIF days Dourdan January 2014!45 WHERE TO GO FROM HERE?
Run Auger until 2023 (+ years) with a detector upgrade that allows us to do mass composition analysis on an event by event basis Elucidate the origin of the cut-off! this will allow for reliable estimates of neutrino and gamma fluxes Search for a proton contribution in the cut-off! with a sensitivity to a fraction of % of proton Prospect for proton astronomy with future detectors will be determined Study of extensive air showers and hadronic multi-particle production! Includes search for new physics Elucidate the origin of the Ankle Search for cosmogenic photons Antoine Letessier Selvon (CNRS/UPMC)!46 FRIF days Dourdan January 2014
36 Antoine Letessier Selvon (CNRS/UPMC)!47 FRIF days Dourdan January 2014