Universal cosmic rays energy spectrum and the mass composition at the 'ankle' and above

• Published in: arXiv.org 2017-06
• Main Authors: Wibig, Tadeusz, Wolfendale, Arnold W
• Format: Article
• Language: English
• Subjects: Anisotropy; Augers; Composition; Cosmic ray showers; Cosmic rays; Dependence; Energy resolution; Energy spectra; Galaxies; High energy astronomy
• ISSN: 2331-8422

We have used recently published data from the Pierre Auger Observatory and the Telescope Array Project to conclude some inferences concerning the origin and composition of ultra high-energy cosmic rays (UHECR). We advocate for model the UHECR flux as a combination of the Galactic and Extragalactic components exchanging the dominant role at the famous feature of the energy spectrum called 'the ankle'. We put a special emphasis on the individual experiment energy resolution and possible biases it introduces. We have eventually combined the data from both big experiments to the one 'world average' UHECR spectrum and we used it, supported by the analysis of the distribution of the Extensive Air Shower (EAS) development maximum depth to find the UHECR mass composition of both: Galactic and Extragalactic components. We studied the dependence of the on mass composition on the cosmic ray source distribution in space. We present results for some models existing in the literature. We found the evidence of the deficit of Extragalactic sources in the vicinity of the Galaxy of the the UHECR, what is in concordance with the small scale anisotropy analysis results.