On the Origin of the Highest Energy Cosmic Rays
نویسنده
چکیده
We present the results of a new estimation of the photodisintegration and propagation of ultrahigh energy cosmic-ray (UHCR) nuclei in intergalactic space. The critical interactions for energy loss and photodisintegration of UHCR nuclei occur with photons of the infrared background radiation (IBR). We have reexamined this problem making use of a new determination of the IBR based on empirical data, primarily from IRAS galaxies, and also collateral information from TeV -ray observations of two nearby BL Lac objects. Our results indicate that a 200 EeV Fe nucleus can propagate 100 Mpc though the IBR. We argue that it is possible that the highest energy cosmic rays observed may be heavy nuclei.
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