Can Ultrahigh Energy Cosmic Rays Come from Gamma-Ray Bursts? II: Cosmic Rays Below the Ankle and Galactic GRB
نویسندگان
چکیده
The maximum cosmic ray energy achievable by acceleration by a relativistic blast wave is derived. It is shown that forward shocks from long GRB in the interstellar medium are powerful enough to produce the Galactic cosmic-ray component just below the ankle at 4 × 10eV, as per an earlier suggestion (Levinson & Eichler 1993). It is further argued that, were extragalactic long GRBs responsible for the component above the ankle as well, the occasional Galactic GRB within the solar circle would contribute more than the observational limits on the outward flux from the solar circle, unless an avoidance scenario, such as intermittency and/or beaming, allows the present-day, local flux to be less than 10 of the average. Difficulties with these avoidance scenarios are noted. Subject headings: Galaxy, cosmic rays, gamma-ray bursts
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