Related papers: Galactic Cosmic Ray Acceleration with Steep Spectr…
Galactic cosmic rays are believed to be accelerated at supernova remnant shocks. Gamma-ray observations of both supernova remnants and associated molecular clouds have been used in several occasions to test (so far quite successfully) this…
One of the most important challenges for the largely accepted idea that Galactic CRs are accelerated in SNR shocks is the maximum energy at which particles can be accelerated. The resonant streaming instability, long invoked for magnetic…
Recent progress suggests we are moving towards a quantitative understanding of the whole cosmic ray spectrum, and that many bumps due to different components and processes hide beneath a relatively smooth total flux between knee and ankle.…
High-energy gamma ray emission has been detected recently from supernovae remnants (SNRs) and their surroundings. The existence of molecular clouds near some of the SNRs suggests that the gamma rays originate predominantly from p-p…
The time-dependent nonlinear kinetic theory for cosmic ray (CR) acceleration in supernova remnants (SNRs) is applied studying the properties of the synchrotron emission from SNRs, in particular, the surface brightness-diameter ($\Sigma-D$)…
It is shown that the nonlinear kinetic theory of cosmic ray (CR) acceleration in supernova remnants (SNRs) describes the shell-type nonthermal X-ray morphology of Cas A, obtained in Chandra observations, in a satisfactory way. The set of…
We derive expressions for the time integrated spectrum of Cosmic Rays (CRs) that are accelerated in a decelerating relativistic shock wave and escape ahead of the shock. It is assumed that at any given time the CRs have a power law form,…
We investigate the escape process of cosmic rays (CRs) from perpendicular shock regions of a spherical shock propagating to a circumstellar medium with the Parker-spiral magnetic field. The diffusive shock acceleration in perpendicular…
Cosmic rays (CRs) generate diffuse emission while interacting with the Galactic magnetic field (B-field), the interstellar gas and the radiation field. This diffuse emission extends from radio, microwaves, through X-rays, to high-energy…
One prediction of particle acceleration in the supernova remnants in the magnetic wind of exploding Wolf Rayet and Red Super Giant stars is that the final spectrum is a composition of a spectrum $E^{-7/3}$ and a polar cap component of…
Nonthermal phenomena are ubiquitous in the Universe, and cosmic rays (CRs) play various roles in different environments. When, where, and how CRs are first generated since the Big Bang? We argue that blast waves from the first cosmic…
Initial discovery of CRs dates back to a century ago (1912). Their identification as particles rather than radiation dates to about 20 years later and in 20 more years also the first suggestion that they were associated with SNRs was in…
Cosmic rays (CRs) are dynamically important for the formation and evolution of galaxies by regulating star formation and by powering galactic outflows. However, to what extent CRs regulate galaxy formation depends on the coupling strength…
Strong astrophysical shocks, diffusively accelerating cosmic rays (CR) ought to develop CR precursors. The length of such precursor $L_{p}$ is believed to be set by the ratio of the CR mean free path $\lambda$ to the shock speed, i.e.,…
Supernova remnants are known to accelerate cosmic-rays from the detection of non-thermal emission in radio waves, X-rays, and gamma-rays. However, the ability to accelerate cosmic-rays up to PeV energies has yet to be demonstrated. The…
The origin of Galactic Cosmic Rays (GCRs) and the potential role of Supernova Remnants (SNRs) as cosmic-ray (CR) accelerators remain subjects of ongoing debate. To shed more light on this topic, we have studied the spectral shape of two…
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…
The origin of cosmic rays above the knee in the spectrum is an unsolved problem. We present a wind model in which interstellar gas flows along a non-rotating, expanding flux tube with a changing speed and cross-sectional area. Cosmic rays…
A shock-accelerated particle flux \propto p^-s, where p is the particle momentum, follows from simple theoretical considerations of cosmic-ray acceleration at nonrelativistic shocks followed by rigidity-dependent escape into the Galactic…
This is the first of a series of papers analysing the Galactic Cosmic Ray composition and origin. We show that the Galactic Cosmic Ray source (GCRS) composition is best described in terms of (i) a general enhancement of the refractory…