On the e${}^{+}$e${}^{-}$ excesses and the knee of the cosmic ray spectra -- hints of cosmic rays acceleration at young supernova remnants

Abstract

Supernova remnants have long been regarded as sources of the Galactic cosmic rays up to petaelectronvolts, but convincing evidence is still lacking. In this work we explore the common origin of the subtle features of the cosmic ray spectra, such as the knee of cosmic ray spectra and the excesses of electron/positron fluxes recently observed by ATIC, H.E.S.S., Fermi-LAT and PAMELA. Numerical calculation shows that those features of cosmic ray spectra can be well reproduced in a scenario with e${}^{+}$e${}^{-}$ pair production by interactions between high energy cosmic rays and background photons in an environment similar to the young supernova remnant. The success of such a coherent explanation serves in turn as an evidence that at least a portion of cosmic rays might be accelerated at young supernova remnants.

11 pages, 3 figures and 1 table. Accepted for publication in ApJL

References in corpus (6)

• Observation of an anomalous positron abundance in the cosmic radiation
• Measurement of the Cosmic Ray e+ plus e- spectrum from 20 GeV to 1 TeV with the Fermi Large Area Telescope
• Cosmic-ray positron fraction measurement from 1 to 30 GeV with AMS-01
• PAMELA data and leptonically decaying dark matter
• A Markov Chain Monte Carlo for Galactic Cosmic Ray physics: I. Method and results for the Leaky Box Model
• Diffusive shock acceleration in radiation dominated environments

Cited by in corpus (6)

• Quantitative study of the AMS-02 electron/positron spectra: implications for the pulsar and dark matter properties
• A dark matter model that reconciles tensions between the cosmic-ray $e^{\pm }$ excess and the gamma-ray and CMB constraints
• Evidence of fresh cosmic ray in galactic plane based on DAMPE measurement of B/C and B/O ratios
• Consistent explanation for the cosmic-ray positron excess in $p$-wave Breit-Wigner enhanced dark matter annihilation
• Explanations of the DAMPE high energy electron/positron spectrum in the dark matter annihilation and pulsar scenarios
• Consistent explanation for the cosmic-ray positron excess in p-wave Sommerfeld-enhanced dark matter annihilation