Related papers: PeVatron Candidate SNR G106.3+2.7 in a Low-density…
Supernova remnant (SNR) G106.3+2.7 was recently found to be one of the few potential Galactic hadronic PeVatrons. Aiming to test how solid the SNR is associated with the molecular clouds (MCs) that are thought to be responsible for hadronic…
We report a discovery of diffuse X-ray emission around the supernova remnant (SNR) G106.3+2.7, which is associated with VER J2227+608 and HAWC J2227+610 and is known as a candidate for a PeV cosmic ray accelerator (PeVatron). We analyze…
A multi-wavelength investigation of the candidate supernova remnant G63.7+1.1 and its surrounding interstellar medium is presented. On the basis of radio continuum data we conclude that the object is a filled-center supernova remnant,…
Cosmic rays (protons and other atomic nuclei) are believed to gain energies of petaelectronvolts (PeV) and beyond at astrophysical particle accelerators called 'PeVatrons' inside our Galaxy. Although a characteristic feature of a PeVatron…
Supernova remnants (SNRs) are believed to be capable of accelerating cosmic rays (CRs) to PeV energies. SNR G106.3+2.7 is a prime PeVatron candidate. It is formed by a head region, where the pulsar J2229+6114 and its boomerang-shaped pulsar…
The youngest known Galactic supernova remnant (SNR) G1.9+0.3 has high-velocity supernova shock beyond 10000 km s-1, and it is considered to be one of the major candidates of a PeVatron. Despite these outstanding properties, the surrounding…
SNR G106.3+2.7 is a complex TeV emitting source whose emission is still poorly understood. It has especially been at the center of numerous discussions on its potential for being a supernova remnant (SNR) PeVatron, since its gamma-ray…
We investigate the interstellar medium (ISM) towards seven TeV gamma-ray sources thought to be pulsar wind nebulae (PWNe) using Mopra molecular line observations at 7mm [CS(1-0), SiO(1-0,v=0)], Nanten CO(1-0) data and the SGPS/GASS HI…
We examine the new Galactic supernova remnant (SNR) candidate, G23.11+0.18, as seen by the Murchison Widefield Array (MWA) radio telescope. We describe the morphology of the candidate and find a spectral index of -0.63+/-0.05 in the…
Recent results obtained with gamma-ray satellites have established supernova remnants as accelerators of GeV hadronic cosmic rays. In such processes, CRs accelerated in SNR shocks interact with particles from gas clouds in their…
The Tibet AS$\gamma$ experiment has measured $\gamma$-ray flux of supernova remnant G106.3+2.7 up to 100 TeV, suggesting it {being} potentially a "PeVatron". Challenge arises when the hadronic scenario requires a hard proton spectrum (with…
We report the extended GeV $\gamma$-ray emission that spatially associated with the high Galactic latitude supernova remnant (SNR) candidate - Calvera's SNR with the Pass 8 data recorded by the {\em Fermi} Large Area Telescope. The…
Recently, the LHAASO Collaboration reported the first very-high-energy gamma-ray catalog, containing 90 TeV sources. Among these sources, 1LHAASO J1929+1846u is located 0.3$^\circ$ west of SNR G54.1+0.3 and also lies within a $+53 \,…
To determine the nature of the PeVatron's emission (hadronic or leptonic), it is essential to characterize the physical parameters of the environment from where it originates. We unambiguously confirm the association of molecular gas with…
The Kepler supernova remnant (SNR) is the only historic supernova remnant lacking a detection at GeV and TeV energies which probe particle acceleration. A recent analysis of Fermi-LAT data reported a likely GeV gamma-ray candidate in the…
G106.3$+$2.7, commonly considered a composite supernova remnant (SNR), is characterized by a boomerang-shaped pulsar wind nebula (PWN) and two distinct ("head" & "tail") regions in the radio band. A discovery of very-high-energy (VHE)…
We model the size distribution of supernova remnants to infer the surrounding ISM density. Using simple, yet standard SNR evolution models, we find that the distribution of ambient densities is remarkably narrow; either the standard…
RX J1713.7$-$3946 is the most remarkable TeV $\gamma$-ray SNR which emits $\gamma$-rays in the highest energy range. We made a new combined analysis of CO and \ion{H}{1} in the SNR and derived the total protons in the interstellar medium…
Supernova remnants (SNRs) have long been considered as one of the most promising sources of Galactic cosmic rays. In the SNR paradigm, petaelectronvolt (PeV) proton acceleration may only be feasible at the early evolution stage, lasting a…
HESS J1641-463 is an unidentified gamma-ray source with a hard TeV gamma-ray spectrum, and thus it has been proposed to be a possible candidate for cosmic ray (CR) accelerators up to PeV energies (a PeVatron candidate). The source spatially…