The Local Bubble in the interstellar medium and the origin of the low energy cosmic rays

TL;DR

This paper investigates how the Local Bubble influences the energy spectra of cosmic rays, suggesting local supernova remnants are primary sources below 200 GV and a recent local supernova remnant dominates at higher rigidities.

Contribution

It proposes a model linking the Local Bubble's supernova remnants to observed cosmic ray spectra, highlighting local sources' roles at different energies.

Findings

Cosmic ray spectra below 200 GV are mainly from Local Bubble supernova remnants.

A single recent supernova remnant likely dominates cosmic rays above 200 GV.

The Local Bubble significantly impacts the origin and energy distribution of low-energy cosmic rays.

Abstract

An analysis of the energy spectra of cosmic rays and particularly the precise data from the AMS-02 experiment support the view about the important role of the Local Bubble in the nearby interstellar medium. It is suggested that the bulk of cosmic rays below about 200 GV of rigidity (momentum/charge ratio) comes from the modest number of supernova remnants in the Local Bubble which appear to have occurred some $10^6$ years ago and contributed to its formation. At higher rigidities the contribution from a 'Local Source', a single supernova remnant generated some $10^5$ years ago seems to dominate up to, at least 1000 GV.