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Structures in the gamma-ray spectrum Z-bursts Topological defects TeV Blazars. Topological defects Decay of TD’s can give rise to UHE cosmic rays Models for the decay of TD favour gamma-ray dominance Gamma-rays from TD decay propagate and can accumulate at GLAST energies.
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Structures in the gamma-ray spectrum • Z-bursts • Topological defects • TeV Blazars
Topological defects • Decay of TD’s can give rise to UHE cosmic rays • Models for the decay of TD favour gamma-ray dominance • Gamma-rays from TD decay propagate and can accumulate at GLAST energies. • Depends on the properties of the IR background and on the intergalactic magnetic field • S. Lee, PRD 58(1998)043004
CMB Radio IR Lee PRD 58(1998)043004
GEV EMISSION FROM TEV BLAZARS AND INTERGALACTIC MAGNETIC FIELDS . G Z. Dai, B. Zhang, L. J. Gou, P. Meszarosand E. Waxman astro-ph/0209091
GeV gamma-rays from TeV gamma-ray emitters • The TeV gamma-rays interact with the IR background and produce electron-positron pairs • Inverse Compton scattering of the IR photons on these electrons/positrons give rise to GeV photons • Flux depends on source activity and the intergalactic magnetic field • Z.G. Dai et al., astro-ph/0209091
Z-bursts • Proposed to explain airshowers above 51019eV • Needs flux of neutrinos above 1021eV • Needs a neutrino mass in the range 0.1 - 10 eV • Needs clustering of relic neutrinos
Z-bursts: • Speculative idea • Payoff can be big! • (Weiler 1999, Fargion, Mele and Salis 1999)
GZK cutoff AGASA data on cosmic ray spectrum (from Päs and Weiler, PRD 63(2001)113005)
Production of a Z-burst Nucleons and photons are produced in the Z-decay with energies that may be above the GZK cutoff. Photons have a wide energy range. E(cosmic) = 4(eV/m) ZeV Päs and Weiler PR D63(2001)113015
Neutrino mass constraints assuming m3 > m2 > m1. The curved line limits from solar and atmospheric data. Päs and Weiler Phys Rev D63(2001)113015
Momentum distribution in hadronic Z-decays Fodor et al. hep-ph/0203198
GLAST Structure in spectrum from collisions on the IR background. Higher energy photons accumulate here Spectra of nucleons, photons and neutrinos. Neutrino mass 1 eV. Ringwald ICRC 2001, hep-ph/0111112
Z-burst best fit for different cosmological evolution parameter . Fodor et al. hep-ph/0203198