相关论文: Cosmic rays from trans-relativistic supernovae
Supernova remnants (SNRs) are widely considered the most likely source of cosmic rays below the knee ($10^{15}$ eV). Studies of GeV and TeV gamma-ray emission in the vicinity of SNRs, in combination with multi-wavelength observations, can…
The death of massive stars and the processes which govern the formation of compact remnants are not fully understood. Observationally, this problem may be addressed by studying different classes of cosmic explosions and their energy…
Observations of cosmic rays with energies above ~ 4 x 10^{10} GeV have inspired several speculative suggestions concerning their origin. The crucial question is whether or not the spectrum exhibits the expected `GZK cutoff' at this energy…
Recent results from the HESS gamma ray telescope have shown the presence of both a diffuse, extended, flux of gamma rays above ~0.4 TeV and discrete sources in and near the Galactic Centre. Here, we put forward a possible explanation in…
The spectra fits to a sample of 34 supernova remnants (Zeng et al., 2019) are updated. $\gamma$-ray spectra of 20 supernova remnants (SNRs) with a soft TeV spectrum are further analyzed. We found that 17 of them can be fitted in the…
The little we do know of the physical conditions in gamma-ray bursters makes them conducive to the acceleration of high-energy cosmic rays, especially if they are at cosmological distances. We find that, with the observed statistics and…
Supernova remnants are known to accelerate cosmic rays (CRs) on account of their non-thermal emission of radio waves, X-rays, and gamma rays. However, the ability to accelerate CRs up to PeV-energies has yet to be demonstrated. The presence…
In 1990's Very High Energy Gamma-ray Astrophysics has dramatically advanced due to the Imaging Air \v{C}erenkov Telescopes(IACTs). After the first detection of TeV gamma-ray emission from the Crab nebula in 1989, several type of TeV…
The X-ray synchrotron emission of each of the young supernova-remnants (SNRs) SN1006, Kepler, Tycho, RCW86 and Cas A, is roughly given by $\nu L_{\nu}\sim 10^{45}\rm{erg}/t$, where $t$ is the remnant's age. The electrons emitting the X-ray…
The possibility that the major part of all extrasolar hadronic cosmic rays with energies above 10 MeV/n is of extragalactic origin is discussed. Recent observational results on the galactocentric cosmic-ray density gradient and very high…
The propagation of cosmic iron nuclei with energies above 10^19 eV from their sources to the Galaxy is discussed by assuming that cosmic rays at ultra-high energies are of extragalactic origin. In extragalactic space, cosmic nuclei interact…
The properties of the Galactic supernova remnant SN 1006 are theoretically reanalysed. Nonlinear kinetic theory is used to determine the acceleration efficiency of cosmic rays (CRs) in the supernova remnant SN 1006. The known range of…
Cosmic rays represent one of the most important energy transformation processes of the universe. They bring information about the surrounding universe, our galaxy, and very probably also the extragalactic space, at least at the highest…
Supernova remnants are widely believed to be a principal source of galactic cosmic rays, produced by diffusive shock acceleration in the environs of the remnant's expanding shock. This review discusses recent modelling of how such energetic…
Star-forming and starburst galaxies are considered as one of the viable candidate sources of the high-energy cosmic neutrino background detected in IceCube. We revisit contributions of supernova remnants (SNRs) and hypernova remnants (HNRs)…
Cosmic rays with energies beyond the Greisen-Zatsepin-Kuzmin `cutoff' at $\sim 4 \times 10^{10}$ GeV pose a conundrum, the solution of which requires either drastic revision of our astrophysical understanding, or new physics beyond the…
We calculate the flux of ultra high energy photons from individual ordinary (i.e. non-superconducting) cosmic strings and compare the results with the sensitivity of current and proposed TeV and EeV telescopes. Our calculations give only…
If cosmic rays with energies <100 TeV originate in the galaxy and are accelerated in shock waves in shell-type supernova remnants (SNRs), gamma-rays will be produced as the result of proton and electron interactions with the local…
We consider the advantages of and the problems associated with hypotheses to explain the origin of ulthrahigh energy cosmic rays (UHECR: E > 10 EeV) and the "trans GZK" cosmic rays (TGZK: E > 100 EeV), both through "old physics"…
Recent studies, supported by updated hadronic interaction models, suggest that the mass composition of ultra-high-energy cosmic rays may be heavier than previously assumed. This has significant implications for source identification, as the…