相关论文: The Most Likely Sources of High Energy Cosmic-Ray …
If supernova remnants (SNRs) are the sites of cosmic-ray acceleration, the associated nuclear interactions should result in observable fluxes of TeV gamma-rays from the nearest SNRs. Measurements of the gamma-ray flux from six nearby,…
A significant fraction of the energy density of the interstellar medium is in the form of high-energy charged particles (cosmic rays). The origin of these particles remains uncertain. Although it is generally accepted that the only sources…
The process that allows cosmic rays to escape from their sources and be released into the Galaxy is still largely unknown. The comparison between cosmic-ray electron and proton spectra measured at Earth suggests that electrons are released…
It has long been speculated that supernova remnants represent a major source of cosmic rays in the Galaxy. Observations over the past decade have ceremoniously unveiled direct evidence of particle acceleration in SNRs to energies…
Supernova remnants (SNRs) are widely believed to be the principal source of galactic cosmic rays. Such energetic particles can produce gamma-rays and lower energy photons via interactions with the ambient plasma. In this paper, we present…
The emission mechanism for hard $\gamma$-ray spectra from supernova remnants (SNRs) is still a matter of debate. Recent multi-wavelength observations of TeV source HESS J1912+101 show that it is associated with an SNR with an age of $\sim…
Recent measurements of cosmic-ray spectra of several individual nuclear species by the CREAM, TRACER, and ATIC experiments indicate a change in the spectral index of the power laws at TeV energies. Possible explanations among others include…
It is thought that Galactic cosmic ray (CR) nuclei are gradually accelerated to high energies (up to ~300 TeV/nucleon, where 1TeV=10^12eV) in the expanding shock-waves connected with the remnants of powerful supernova explosions. However,…
Supernova remnants (SNRs) are thought to be the most plausible sources of Galactic cosmic rays. One of the principal questions is whether they are accelerating particles up to the maximum energy of Galactic cosmic rays ($\sim$PeV). In this…
One of the most essential but uncertain processes for producing cosmic-rays (CRs) and their spectra is how accelerated particles escape into the interstellar space. We propose that the CR electron spectra at >~TeV energy can provide a…
Supernova remnants (SNRs) have long been hypothesized as the main source of Galactic Cosmic Rays up to PeV energies. Some of them have indeed been shown to accelerate protons to TeV energies and above. But which of them are indeed efficient…
Supernova remnants (SNRs) are likely to be significant sources of cosmic rays up to the knee of the local cosmic-ray (CR) spectrum. They produce gamma-rays in the very-high-energy (VHE) ($E>0.1$ TeV) range via: hadronic interactions with…
It has been known for over 50 years that the radio emission from shell supernova remnants (SNRs) indicates the presence of electrons with energies in the GeV range emitting synchrotron radiation. The discovery of nonthermal X-ray emission…
The quest for the origin of cosmic ray (CRs) is a fundamental issue in astrophysics. Shocks of supernova remnants (SNRs) have been considered as the dominant contributors to Galactic CRs below the spectral knee near $\sim 3$…
We consider a possibility of identification of sources of cosmic rays (CR) of the energy above 1 TeV via observation of degree-scale extended gamma-ray emission which traces the locations of recent sources in the Galaxy. Such emission in…
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…
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…
SNRs are likely to be significant sources of Galactic cosmic rays up to the knee. They produce gamma rays in the very-high-energy (E>100 GeV) range mainly via two mechanisms: hadronic interactions of accelerated protons with the…
Supernova remnants (SNRs) are the prime candidates for the acceleration of the Galactic Cosmic Rays. Tracers for interactions of Cosmic Rays with ambient material are gamma rays at TeV energies, which can be observed with ground based…
We study the emission from an old supernova remnant (SNR) with an age of around 10^5 yrs and that from a giant molecular cloud (GMC) encountered by the SNR. When the SNR age is around 10^5 yrs, proton acceleration is efficient enough to…