Radioactivity and Electron Acceleration in Supernova Remnants

Abstract

We argue that the decays of radioactive nuclei related to ${}^{44}$Ti and ${}^{56}$Ni ejected during supernova explosions can provide a vast pool of mildly relativistic positrons and electrons which are further accelerated to ultrarelativistic energies by reverse and forward shocks. This interesting link between two independent processes - the radioactivity and the particle acceleration - can be a clue for solution of the well known theoretical problem of electron injection in supernova remnants. In the case of the brightest radio source Cas A, we demonstrate that the radioactivity can supply adequate number of energetic electrons and positrons for interpretation of observational data provided that they are stochastically pre-accelerated in the upstream regions of the forward and reverse shocks.

6 pages, 1 figure, revised version accepted to Phys.Rev. D

References in corpus (12)

• Observation of an anomalous positron abundance in the cosmic radiation
• The Cassiopeia A Supernova was of Type IIB
• On possible interpretations of the high energy electron-positron spectrum measured by the Fermi Large Area Telescope
• Diffusive Shock Acceleration with Magnetic Amplification by Non-resonant Streaming Instability in SNRs
• The signature of 44Ti in Cassiopeia A revealed by IBIS/ISGRI on INTEGRAL
• Characterizing the non-thermal emission of Cas A
• Fast Variability of Nonthermal X-Ray Emission in Cassiopeia A: Probing Electron Acceleration in Reverse-Shocked Ejecta
• Observations of the shell-type SNR Cassiopeia A at TeV energies with VERITAS
• Particle acceleration mechanisms
• Radioactive Scandium in the Youngest Galactic Supernova Remnant G1.9+0.3
• Annihilation emission from young supernova remnants
• The role of ionization in the shock acceleration theory

Cited by in corpus (6)

• Astrophysical models for the origin of the positron "excess"
• Origin of Cosmic Rays
• Galactic annihilation emission from nucleosynthesis positrons
• Plus Charge Prevalence in Cosmic Rays: Room for Dark Matter in the Positron Spectrum
• Electrons and Positrons in Cosmic Rays
• Cosmic ray positrons from a local, middle-aged supernova remnant