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Astrophysics of high energy cosmic-rays Eli Waxman Weizmann Institute, ISRAEL “New Physics”: talk by M. Drees Bhattacharjee & Sigl 2000
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Cosmic ray flux and Composition E [GeV] log [dJ/dE] 110 610 E -2.7 E -3 Heavy Nuclei Protons Light Nuclei (p?) U cr (1GeV)=1 eV/cm 3 Galactic plane enhancement Isotropy Galactic X-Galactic [Blandford & Eichler, Phys. Rep. 87; Axford, ApJS 94; Nagano & Watson, Rev. Mod. Phys. 00]
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Challenge I: Acceleration R B v v
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Brightest known sources AGN jets (steady): ~ few requires L>10 47 erg/s Few, brightest AGN GRBs (transient): ~ 300 requires L>10 51 erg/s Average L ~10 52 erg/s [Srittmatter 82 Biermann & Strittmatter 87] [Waxman 95; Vietri 95; Milgrom & Usov 95]
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The Suspects losses 1/ [Hillas 84; Arisaka 02]
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Comments on “ Magnetars ” Newborn Neutron stars (Hypothesis) with: B~10 14 G, ~10 4 /sec L EM ~10 50 erg/s for t<1 min. Some difficulties: Wind should penetrate envelope with <10 -12 M sun entrainment Acceleration mechanism: Unknown NS ~1 M sun envelope EM wind [e.g. Blasi, Epstein, Olinto 00; Arons 02]
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Challenge II: Propagation (GZK) n (p) +(0)+(0) CMB p 10 100 1000 0.51.03.0 [Greisen 66; Zatsepin & Kuzmin 66]
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Model Fly ’ s Eye fit for Galactic heavy (<10 19 eV): J G ~E -3.50 X-Galactic protons: Generation spectrum (shock acceleration): Generation rate (GRB motivated): Redshift evolution ~ SFR (GRB motivated). [Waxman 95]
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The Data
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Data- Calibrated at 10 19 eV
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Model vs. Data X-G Model: [Bahcall & Waxman 02] Ruled out 7 55
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Conclusions are Robust
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Data/Model consistency Yakutsk, Fly ’ s Eye, HiRes: Consistent with XG protons: + GZK AGASA (25% of total exposure): Consistent below 10 20 eV Excess above 10 20 eV: 2.2+/-0.8 8 observed New source/New physics/ 25% energy Local inhomogeneity over-estimate Need: Large, hybrid 10 18 eV to 10 20 eV detector (Auger) ?
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The Auger Observatory: 10 3.5 km 2 [Cronin 92, Watson 93]
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Gamma-ray Bursts M on ~1 Solar Mass BH Relativistic Outflow e - acceleration in Collisionless shocks e - Synchrotron MeV ’s L ~10 52 erg/s ~300 [Meszaros, ARA&A 02]
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Proton/electron acceleration Protons Acceleration: Particle spectrum: p energy production: Electrons MeV ’ s: spectrum energy production [Waxman 95] [Frail et al. 01 Schmidt 01]
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GZK: Sources AGN, Radio-galaxies GRBs : For R GRB (z=0)~0.5/Gpc 3 yr Prediction: p D B [Schmidt 01] [Waxman 95, 01] [Miralda-Escude & Waxman 96]
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GRBs: An illustrative example [Miralda-Escude & Waxman 96 ]
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GRB Model Predictions <2x10 20 eV: Homogeneous + GZK >3x10 20 eV: Few, narrow spectrum sources Fluctuations (no homogeneous GZK) For more: Lec. Notes Phys. review (astro-ph/0103186)
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“ Standard Model ” GRB ’ s Weak dependence on model parameters [Waxman & Bahcall 97, 99] [Rachen & Meszaros 98; Guetta, Spada & Waxman 01]
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Diffuse Flux Bound Observed J CR (>10 19 eV) p losses on CMB z<0.25 For Sources with p <1: Strongest know z evolution (QSO, SFR): [Waxman & Bahcall 99, Bahcall & Waxman 01]
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p for known sources pp ’’ n ++ e+e+ e-e-
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Antares (0.1 Gton) Nemo (1 Gton) Anita (Radio, Balloon)
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The AMANDA South-pole experiment
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AMANDA neutrino event [Andres et al., Nature 01]
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The Mediterranean ANTARES experiment
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Summary Yakutsk, Fly ’ s Eye, HiRes: Consistent with GZK AGASA: >10 20 eV excess Main Challenge: Astrophysical accelerator physics Candidate: GRBs Hybrid, 10 3.5 km 2 Auger: GZK spectrum; Constraints on astro. sources UHE CRs High energy sources: 1--10 3 TeV: 1 km 3 (Optical Cerenkov) detectors Amanda, Antares, Nestor, IceCube, Nemo >>10 3 TeV: >>1 km 3 (Radio Cerenkov) detectors Anita, Rice
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telescopes: some prospects GRB detection appearance Lorentz Inv. (1-v/c : 10 -16 ), Weak equivalence principle ( L/c 3 : 10 -6 )
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