Newly Born Pulsars as Sources of High and Ultrahigh Energy Cosmic Rays Ke Fang University of Chicago...
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Newly Born Pulsars as Sources of High and Ultrahigh Energy Cosmic Rays Ke Fang University of Chicago ISCRA - Jul 9, 2012 1 KF, Kotera, Olinto 2012, ApJ, 750, 118 KF, Kotera, Olinto 2012, in prep
Transcript of Newly Born Pulsars as Sources of High and Ultrahigh Energy Cosmic Rays Ke Fang University of Chicago...
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Newly Born Pulsars as Sources of High and
Ultrahigh Energy Cosmic RaysKe Fang
University of ChicagoISCRA - Jul 9, 2012
KF, Kotera, Olinto 2012, ApJ, 750, 118 KF, Kotera, Olinto 2012, in prep
GRB AGN Clusters Pulsars
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UHECR Observational FactsEnergy Spectrum
Chemical Composition
TA favors light
composition
Pedro Facal San Luis, ICRC 2011 2
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Abbasi et al. 2009Abraham et al. 2010bKotera & Olinto 2011
Fe-peaked elements strippedoff star surface by E-field
I Newly Born PulsarsHeavy nuclei abundant
Fast rotational speed
Strong magnetic field
Ruderman & Sutherland 75, Arons & Scharlemann 79, Blasi et. al 00,Arons 03, Bednarek & Bartosik 04, K.F., Kotera, Olinto 12
cosmic ray charge
wind acc. efficiency = 10%
Injection index too hard!
P ~ 0.6 ms
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B ~ 1012 G
toy model
const velocity
column density
ejecta energy ejecta mass
Unipolar induction
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Pulsars that allow escapeEej=1052 ergsMej=10 Msun
η=0.1
UHE Protons can hardly escape (except for very dilute envelope)
UHE Irons can be accelerated and escape fromms pulsar Ω ~ 104 s-1 with B ~ 1012 – 1013 G
Two competing timescales:
Time to escape
CR Life time
To successfully escape:
Our successful UHECR source: ms pulsar in core-collapse supernova
Upper limit of rotational speed
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Simulation of Injected and Escaped Spectrum
Proton Iron
Pure Protons above 10 EeV cannot escape!
~E-2
Injected
escapedlight heavy
Monte-Carlo propagation, hadronic interactions with EPOS + CONEX
Injected
escaped primary
escaped secondary
dN/d log B
11.55 12.65 13.75log B [G]
dN/d P
150 300 450 600 P [ms]
Faucher-Giguere & Kaspi 06
Pulsar distribution in the galaxy
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).
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Preliminary
Contribution from Extragalactic pulsar population
Upper limit of rotational speed
< 0.01%
galaxy density = 0.02 Mpc-3
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Has to be another source!
Extragalactic sourcesGalactic sources
dN/d log B
11.55 12.65 13.75log B [G]
dN/d P
150 300 450 600 P [ms]
Faucher-Giguere & Kaspi 06 Galactic Pulsar?
Upper limit of rotational speed
SNR EG Pulsar AGN Clusters
Spectrum & Composition above the knee
GRB
SNR, Fe tail Emax= 1016-17 eV
Intermediate, not Fe/P!
EG, Proton
Gal Pulsar
SNR, Fe tail Emax= 1016-17 eV
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KF, Kotera, Olinto in prep
Contribution from Galactic and Extragalactic pulsar population
Conclusion II: Galactic and Extragalactic pulsars can be the dominant source above ~1016 eV !
Fit with Auger data3%Fe+22%CNO+40%He+35%P
Fit with TA data23%Fe+22%CNO+40%He+15%P
Halo Height
B-field coherence length
