High-energy cosmic rays and neutrinos from semirelativistic hypernovae

Xiang-Yu Wang, Soebur Razzaque, Peter Mészáros, Zi-Gao Dai
2007 Physical Review D  
The origin of the ultrahigh-energy (UHE) cosmic rays (CRs) from the second knee (∼6×10^17eV) above in the CR spectrum is still unknown. Recently, there has been growing evidence that a peculiar type of supernovae, called hypernovae, are associated with sub-energetic gamma-ray bursts (GRBs), such as SN1998bw/GRB980425 and SN2003lw/GRB031203. Such hypernovae appear to have high (up to mildly relativistic) velocity ejecta, which may be linked to the sub-energetic GRBs. Assuming a continuous
more » ... ution of the kinetic energy of the hypernova ejecta as a function of its velocity E_k∝ (Γβ)^-α with α∼ 2, we find that 1) the external shock wave produced by the high velocity ejecta of a hypernova can accelerate protons up to energies as high as 10^19 eV; 2) the cosmological hypernova rate is sufficient to account for the energy flux above the second knee; and 3) the steeper spectrum of CRs at these energies can arise in these sources. In addition, hypernovae would also give rise to a faint diffuse UHE neutrino flux, due to pγ interactions of the UHE CRs with hypernova optical-UV photons.
doi:10.1103/physrevd.76.083009 fatcat:fxjokqp2qjhvhkxbcrvy56j5xy