相关论文: The Hunt for Pevatrons: The Case of Supernova Remn…
Cosmic rays (CRs) are charged particles that arrive at Earth isotropically from all directions and interact with the atmosphere. The presence of a spectral knee feature seen in the CR spectrum at $\sim$3 PeV energies is an evidence that…
The origin of Galactic Cosmic Rays (CRs) and the possibility of Supernova Remnants (SNRs) being potential CR accelerators is still an open debate. The charged CRs can be detected indirectly by the {\gamma}-ray observatories through the…
The supernova remnant hypothesis for the origin of Galactic cosmic rays has passed several tests, but the firm identification of a supernova remnant pevatron, considered to be a decisive step to prove the hypothesis, is still missing. While…
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 $\sim 3$…
The recent HESS detections of supernova remnant shells in TeV gamma-rays confirm the theoretical predictions that supernova remnants can operate as powerful cosmic ray accelerators. If these objects are responsible for the bulk of galactic…
The local Cosmic Ray (CR) energy spectrum exhibits a spectral softening at energies around 3~PeV. Sources which are capable of accelerating hadrons to such energies are called hadronic PeVatrons. However, hadronic PeVatrons have not yet…
The problem in identifying the sites of origin of Galactic Cosmic Rays (CRs) is reviewed. Recent observational evidence from very-high energy (VHE, energies above 100 GeV) gamma-ray measurements is in contradiction with the surmise that…
The recent detection of 12 gamma-ray Galactic sources well above E > 100 TeV by the LHAASO observatory has been a breakthrough in the context of Cosmic Ray (CR) origin search. Although most of these sources are unidentified, they are often…
Supernova remnants (SNRs) have long been considered to be the dominant source of Galactic cosmic rays, which implied that they provided most of the energy to power cosmic rays as well as being PeVatrons. The lack of evidence for PeV cosmic…
Identification of the cosmic-ray (CR) `PeVatrons', which are sources capable of accelerating particles to $\sim10^{15}$ eV energies and higher, may lead to resolving the long-standing question of the origin of the spectral feature in the…
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…
The existence of a "knee" at energy ~1 PeV in the cosmic-ray spectrum suggests the presence of Galactic PeV proton accelerators called "PeVatrons". Supernova Remnant (SNR) G106.3+2.7 is a prime candidate for one of these. The recent…
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…
Galactic supernova remnants (SNRs) are thought to accelerate cosmic rays (CRs) to several PeV energies, but this has yet to be confirmed as general behavior. Although several sources show ~100 TeV gamma rays, their hadronic origin is…
Several gamma-ray observatories have discovered photons of cosmic origin with energies in the PeV ($10^{15}\,\text{eV}$) range. Photons at these energies might be produced as by-products from particle acceleration in so-called PeVatrons,…
The Pevatron Test Statistic (PTS) is applied to data from $\gamma$-ray observatories to test for the origin of Cosmic Rays (CRs) at energies around the knee of the CR spectrum. Several sources are analyzed within hadronic emission models.…
Supernova remnants are often presented as the most probable sources of Galactic cosmic rays. This idea is supported by the accumulation of evidence that particle acceleration is happening at supernova remnant shocks. Observations in the TeV…
Despite tantalizing evidence that supernova remnants (SNRs) are the source of Galactic cosmic rays (CRs), including the recent detection of a spectral signature of hadronic gamma-ray emission from two SNRs, their origin in aggregate remains…
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,…
GeV and TeV emission from the forward shocks of supernova remnants (SNRs) indicates that they are capable particle accelerators, making them promising sources of Galactic cosmic rays (CRs). However, it remains uncertain whether this…