Explanation of nearby SNRs for primary electron excess and proton spectral bump

TL;DR

This paper confirms a primary electron excess using AMS-02 data, attributes it mainly to the Monogem supernova remnant, and predicts a spectral hardening at TeV energies, with implications for proton spectra.

Contribution

It demonstrates that the Monogem supernova remnant can explain both the primary electron excess and proton spectral bump observed in recent data.

Findings

Monogem can account for the primary electron excess.

Electron spectrum may harden again at a few TeVs due to Vela.

Both electron excess and proton bump could originate from Monogem.

Abstract

Several groups have reported a possible excess of primary electrons at high energies with the joint fit of the positron fraction and total electron/positron spectra. With the latest release of high-precision electron/positron spectra measured by AMS-02, we further confirm this excess by fitting $\Delta\Phi$ $\rm(i.e., \Phi_{e^-}-\Phi_{e^+})$ data in this work. Then we investigate the contribution of a single nearby supernova remnant to the primary electron excess and find that Monogem can reasonably account for this excess. Moreover, we predict that the electron spectrum may harden again at a few TeVs due to Vela's contribution. DAMPE, which can accurately measure electrons at TeV scale, is expected to provide the robust test of this new spectral feature in the near future. Finally, we fit the proton spectrum data of DAMPE with Monogem or Loop I. We find that both the primary electron excess and the proton spectral bump could be mainly generated by Monogem.