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Newly Born Pulsars as Sources of High and Ultrahigh Energy Cosmic Rays

Newly Born Pulsars as Sources of High and Ultrahigh Energy Cosmic Rays. Ke Fang University of Chicago ISCRA - Jul 9, 2012. KF, Kotera , Olinto 2012, ApJ , 750, 118 KF, Kotera , Olinto 2012, in prep. UHECR Observational Facts. GRB AGN Clusters Pulsars. ✓✓ ✓✓. ✗✗✗✓.

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Newly Born Pulsars as Sources of High and Ultrahigh Energy Cosmic Rays

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  1. Newly Born Pulsars as Sources of High and Ultrahigh Energy Cosmic Rays Ke Fang University of Chicago ISCRA - Jul 9, 2012 KF, Kotera, Olinto 2012, ApJ, 750, 118 KF, Kotera, Olinto 2012, in prep

  2. UHECR Observational Facts GRB AGN Clusters Pulsars ✓✓✓✓ ✗✗✗✓ Energy Spectrum Chemical Composition TA favors light composition Abbasi et al. 2009 Abraham et al. 2010b Kotera& Olinto2011 Pedro Facal San Luis, ICRC 2011

  3. I Newly Born Pulsars Fe-peaked elements stripped off star surface by E-field P ~ 0.6 ms Heavy nuclei abundant Fast rotational speed Strong magnetic field B ~ 1012 G • Unipolar induction cosmic ray charge wind acc. efficiency = 10% Injection index too hard! toy model const velocity column density ejecta energy • ejecta mass Ruderman & Sutherland 75, Arons& Scharlemann79, Blasiet. al 00, Arons 03, Bednarek & Bartosik 04, K.F., Kotera, Olinto 12

  4. Eej=1052 ergs Mej=10 Msun η=0.1 Pulsars that allow escape Upper limit of rotational speed Two competing timescales: Time to escape CR Life time To successfully escape: UHE Protonscan hardly escape (except for very dilute envelope) UHE Irons can be accelerated and escape from ms pulsar Ω ~ 104 s-1 with B ~ 1012 – 1013 G Our successful UHECR source: ms pulsar in core-collapse supernova

  5. Simulation of Injected and Escaped Spectrum Monte-Carlo propagation, hadronicinteractions with EPOS + CONEX Proton Iron Injected Injected ~E-2 Pure Protons above 10 EeV cannot escape! light heavy escaped escaped primary escaped secondary

  6. Contribution from Extragalactic pulsar population Pulsar distribution in the galaxy galaxy density = 0.02 Mpc-3 dN/d log B 11.55 12.65 13.75 log B [G] Preliminary dN/d P < 0.01% Upper limit of rotational speed P [ms] 150 300 450 600 Faucher-Giguère & Kaspi 06 Conclusion I: ≲ 0.01% of extragalactic pulsar (normal pulsar birth rate 10-4 Mpc-3 yr-1) can reproduce measured UHECR flux, spectrum and composition (by Auger).

  7. Spectrum & Composition above the knee Galactic Pulsar? Faucher-Giguère & Kaspi 06 dN/d log B Has to be another source! log B [G] Gal Pulsar 11.55 12.65 13.75 dN/d P SNR, Fe tail Emax= 1016-17 eV EG, Proton P [ms] 150 300 450 600 Upper limit of rotational speed Galactic sources Extragalactic sources SNR EG Pulsar AGN Clusters GRB Intermediate, not Fe/P!

  8. Contribution from Galactic and Extragalactic pulsar population Fit with Auger data 3%Fe+22%CNO+40%He+35%P Fit with TA data 23%Fe+22%CNO+40%He+15%P B-field coherence length Halo Height SNR, Fe tail Emax= 1016-17 eV Conclusion II: Galactic and Extragalactic pulsars can be the dominant source above ~1016eV ! KF, Kotera, Olinto in prep 8

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