Spectrum and mass composition of cosmic rays in the energy range 10^15-10^18 eV derived from the Yakutsk array data

TL;DR

This study analyzes cosmic ray spectrum and composition in the 10^15-10^18 eV range using Yakutsk array data, revealing spectral features possibly linked to galactic heavy nuclei escape, with improved measurement precision from 2000-2010.

Contribution

It provides new, precise measurements of cosmic ray spectrum and composition in the 10^16-10^18 eV range, supporting models of galactic and extragalactic origins.

Findings

Detection of a spectral feature possibly related to heavy nuclei escape from the Galaxy.

Enhanced data set from 2000-2010 improves spectrum accuracy.

Cosmic ray composition analysis supports galactic and extragalactic origin hypotheses.

Abstract

A spectrum of cosmic rays within energy range 10^15 - 3x10^17 eV was derived from the data of the small Cherenkov setup, which is a part of the Yakutsk complex EAS array. In this, work a new series of observation is covered. These observations lasted from 2000 till 2010 and resulted in increased number of registered events within interval 10^16 - 10^18 eV, which in turn made it possible to reproduce cosmic ray spectrum in this energy domain with better precision. A sign of a thin structure is observed in the shape of the spectrum. It could be related to the escape of heavy nuclei from our Galaxy. Cosmic ray mass composition was obtained for the energy region 10^16 - 10^18 eV. A joint analysis of spectrum and mass composition of cosmic rays was performed. Obtained results are considered in the context of theoretical computations that were performed with the use of hypothesis of galactic and meta-galactic origin of cosmic rays.