Gamma-ray lines in solar flares with proton spectra measured by PAMELA experiment

Abstract

During the solar flares protons and heavier ions are accelerated up to GeV energies. Accelerated ions can escape the Sun and be registered directly on spacecraft or penetrate into the solar atmosphere and then produce gamma-ray lines as the result of nuclear reactions. Previous studies revealed very poor correlation between fluxes of interplanetary ions and gamma-ray line emission. In this work we focus on joint observations of interplanetary solar energetic particles registered by PAMELA experiment and gamma-ray emission registered by Konus-Wind instrument in hard X-ray and soft gamma-ray ranges. This study confirmed the previous results: during the period from 2006 to 2014 there were only two solar flares registered both by PAMELA and Konus-Wind at energies above 1 MeV. We analyze gamma-ray spectrum for one of these flares and make suggestions about the reasons for the low correlation between interplanetary solar accelerated ions and accelerated ions interacted in the solar atmosphere.