Related papers: Gamma-ray emission from middle-aged supernova remn…
Supernovae constitute a critical source of energy input to the interstellar medium (ISM). In this short review, we focus on their latest phase of evolution, the supernova remnants (SNRs). We present observations of three old SNRs that have…
The environment of supernova remnants (SNRs) is a key factor in their evolution, particularly at later stages of their existence. It is often assumed that mixed-morphology (MM) SNRs evolve in very dense environments, and that their…
Diffusive shock acceleration in supernova remnants is the most widely invoked paradigm to explain the Galactic cosmic ray spectrum. Cosmic rays escaping supernova remnants diffuse in the interstellar medium and collide with the ambient…
We report the detection of high-energy $\gamma$-ray emission in the vicinity of G172.8+1.5, which is debated as a Supernova remnant (SNR) or an ionized hydrogen (H$_{\rm{II}}$) region. Using 16-yr Pass 8 data from Fermi Large Area Telescope…
The proof of cosmic ray (CR) origin in supernova remnants (SNR) must hinge on full consistency of the CR acceleration theory with the observations; direct proof is impossible because of the orbit stochasticity of CR particles. Recent…
The escape process of particles accelerated at supernova remnant (SNR) shocks is one of the poorly understood aspects of the shock acceleration theory. Here we adopt a phenomenological approach to study the particle escape and its impact on…
The X-ray emission from a supernova remnant (SNR) is a powerful diagnostic of the state of the shocked plasma. The temperature (kT) and the emission measure (EM) of the shocked-gas are related to the energy of the explosion, the age of the…
A rapidly growing amount of evidences, mostly coming from the recent gamma-ray observations of Galactic supernova remnants (SNRs), is seriously challenging our understanding of how particles are accelerated at fast shocks. The cosmic-ray…
Galactic cosmic rays (CRs) are believed to be accelerated at supernova remnant (SNR) shocks. In the hadronic scenario the TeV gamma-ray emission from SNRs originates from decaying pions that are produced in collisions of the interstellar…
We examine the hypothesis that some supernova remnants (SNRs) may be responsible for some unidentified gamma-ray sources detected by EGRET instrument aboard the Compton Gamma Ray Observatory. If this is the case, gamma-rays are produced via…
We study the origin of gamma rays from the supernova remnant (SNR) RX J1713.7-3946. Using an analytical model, we calculate the distribution of cosmic rays (CRs) around the SNRs. Motivated by the results of previous studies, we assume that…
We report on the likely detection of gamma-ray emission from the supernova remnant (SNR) Kesteven 27 (Kes 27). We analyze 5.7 yr Fermi Large Area Telescope data of the SNR region and find an unresolved source at a position consistent with…
The spectrum of cosmic rays (CRs) is affected by their escape from an acceleration site. This may have been observed not only in the gamma-ray spectrum of young supernova remnants (SNRs) such as RX J1713.7-3946, but also in the spectrum of…
We aim to elucidate cosmic ray (CR) propagation in the weakly ionized environments of supernova remnants (SNRs) basing our analysis on the cosmic ray cloud (CRC) model developed by \citet{2013ApJ...768...73M} and…
The optical and near-IR emission from some classes of supernovae (SNe), including Type IIn and possibly some super-luminous SNe, is likely powered by a collision between the SN ejecta and dense circumstellar material (CSM). We argue that…
Until now, providing an experimental unambiguous proof of Cosmic Ray (CR) origin has been elusive. The SuperNova Remnant (SNR) study showed an increasingly complex scenario with a continuous elaboration of theoretical models. The…
The work presented in this thesis is focused on the interacting supernova remnants (iSNRs), a class of gamma-ray emitting SNR where the radiation arise from the interaction of the SNR with a massive molecular cloud. At the moment only 16…
Recent gamma ray observations show that middle aged supernova remnants interacting with molecular clouds can be sources of both GeV and TeV emission. Models involving re-acceleration of pre-existing cosmic rays in the ambient medium and…
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…
We present a simple phenomenological model of hadronic interaction between protons accelerated in an old supernova remnant (SNR) and cold protons situated within the associated molecular clouds (MCs). The accelerated protons from the old…