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تسجيل مستخدم جديدDoes the Geminga $gamma$-ray halo imply slow diffusion around pulsars?
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The propagation of cosmic-ray electrons and positrons in the proximity of the Geminga pulsar is examined considering the transition from the quasi-ballistic, valid for the most recently injected particles, to the diffusive transport regime. For typical interstellar values of the diffusion coefficient, the quasi-ballistic regime dominates the lepton distribution up to distances of a few tens of parsec from the pulsar for particle energies above $sim 10$ TeV. When such transition is taken into account, a good fit to the HAWC $gamma-$ray data around Geminga is obtained without the need to invoke a strong suppression of the diffusion coefficient.
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L. Guillemot (for the Fermi LAT Collaboration
, for the Fermi Pulsarn Search Consortium
,
2012
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