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Cosmic Rays. 1912 discovered by Victor Hess (after Wilson & others) Energy range : ~ 10 9 eV to > 10 20 eV 1938 Pierre Auger discovered Extensive Air Showers (EAS). Sky Maps. COBE. Galactic Photons show the Galaxy. Cosmic Rays are isotropic. Cosmic Ray Spectrum.
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Cosmic Rays • 1912 discovered by Victor Hess • (after Wilson & others) • Energy range: • ~ 109 eV to > 1020 eV • 1938Pierre Auger discovered • Extensive Air Showers (EAS)
Sky Maps COBE Galactic Photons show the Galaxy Cosmic Rays are isotropic
Cosmic Ray Spectrum 32 orders of magnitude 12 orders of magnitude
CR Spectrum x E2.7 x E3 Features? 32 orders of magnitude Is there an end? 12 orders of magnitude
CR Spectrum Direct Measurements E-2.7 Air Shower Measurements 32 orders of magnitude E-3.1 12 orders of magnitude
The ‘knee’ at 31015 eV E2.7F E (eV)
A ‘second knee’ at 51017 eV ? Extra Galactic Galactic Knee 1 Knee 2 Ankle E3F and an ‘ankle’ at 31018 eV
CR Spectrum 2 power laws losses or coincidence E-2.7 32 orders of magnitude E-3.1 12 orders of magnitude
Cosmic Ray Showers One (tiny) Ultra High Energy Particle starts a shower that becomes many km2 of lower energy particles
AGASA 100 km2 scintillators + muon detectors Ground Arrays: Volcano Ranch Yakutsk Haverah Park SUGAR Akeno
Auger South 450 stations deployed! 2 sites Fluorescence 12 telescopes complete 400 working tanks
2 Ultra-High Energy Cosmic Ray Observatories Fluorescence detectors Fly’s Eye
Fluorescence Telescope 16 x 16 PMT array 3 m diameter spherical mirror
6 doublets 1 triplet above 4 x 1019 eV < 2.5 deg above 1019 eV Log E>19.6 Are UHECRs clustered? AGASA - yes?
HiRes - Utah HiRes-I Monocular Data, E > 1019.5 eV No clustering? HiRes-I Monocular Data, E > 1018.5 eV Upper limit of 4 doublets (90% c.l.) in HiRes-I monocular dataset. HiRes Stereo
UHECR come from nearby AGN? Auger Several UHECRs from Cen A? Log E>19.6 Circles = UHECR with E > 5.7 x 1019 eV, red x’s are AGN, Blue = Auger coverage, white x = Cen A
-resonance multi-pions High Energy Proton sees Cosmic Microwave Background as High Energy Gamma Rays! WMAP p+cmb + p + 0 n + + Proton Horizon GZK Cutoff Greisen ‘66, Zatsepin & Kuzmin ‘66
Observed High Energy Spectrum - AGASA AGASA: ~ 11 events above 1020 eV!!!