Related papers: Cosmic-ray acceleration in young protostars
Massive stars blow powerful winds and eventually explode as supernovae. By doing so, they inject energy and momentum in the circumstellar medium, which is pushed away from the star and piles up to form a dense and expanding shell of gas.…
The nonthermal radiation observed from a handfull of clusters of Galaxies is the proof that particle acceleration occurs in the intracluster medium. It is often believed that shock surfaces associated with either mergers of clusters of…
Laser accelerated protons can be a complimentary source for treatment of oncological diseases to the existing hadron therapy facilities. We demonstrate how the protons, accelerated from near-critical density plasmas by laser pulses having…
In the past two decades, laser-accelerated ion sources and their applications have been intensely researched. Recently, it has been shown through experiments that proton beams with characteristics comparable to those obtained with solid…
The strong shocks in young supernova remnants (SNRs) should accelerate cosmic rays (CRs) and no doubt exists that relativistic electrons are produced in SNRs. However, direct evidence that SNRs produce CR nuclei depends on seeing an…
We present results from the first three-dimensional radiation hydrodynamical calculations to follow the collapse of a molecular cloud core beyond the formation of the stellar core. We find the energy released by the formation of the stellar…
The conditions for the fragmentation of the baryonic component during merging of dark matter halos in the early Universe are studied. We assume that the baryonic component undergoes a shock compression. The characteristic masses of…
Pulsar wind nebulae (PWNe) are outstanding accelerators in Nature, in the sense that they accelerate electrons up to the radiation reaction limit. Motivated by this observation, this paper examines the possibility that young pulsar wind…
Although Galactic cosmic rays (protons and nuclei) are widely believed to be dominantly accelerated by the winds and supernovae of massive stars, definitive evidence of this origin remains elusive nearly a century after their discovery [1].…
Identifying the accelerators of Galactic cosmic ray protons (CRs) with energies up to a few PeV ($10^{15}$ eV) remains a theoretical and observational challenge. Supernova remnants (SNRs) represent strong candidates, as they provide…
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…
We present the main features in the evolution of the gas pressure in star forming regions, from the formation of the parental cloud to the moment when the region is pressurized by interacting stellar winds. The main processes for cloud…
It is argued that if cosmic rays penetrate into molecular clouds, the total energy they lose can exceed the energy from galactic supernovae shocks. It is shown that most likely galactic cosmic rays interacting with the surface layers of…
Colliding collisionless shocks appear in a great variety of astrophysical phenomena and are thought to be possible sources of particle acceleration in the Universe. We have previously investigated particle acceleration induced by single…
Outflows and winds launched from young stars play a crucial role in the evolution of protostars and the early stages of planet formation. However, the specific details of the mechanism behind these phenomena, including how they affect the…
Some general features of cosmic ray acceleration are summarized along with some inferences that can be drawn concerning the origin of the UHE component. The UHE luminosity density is found to be similar to that derived for GeV cosmic rays…
We investigate the formation of protostellar clusters during the collapse of dense molecular cloud cores with a focus on the evolution of potential and kinetic energy, the degree of substructure, and the early phase of mass segregation. Our…
Protostellar core formation is probably much more dynamic, and magnetic fields are probably much less important, than has been previously assumed in the standard model of low-mass star formation. This revised picture has important…
Star and planet formation are inextricably linked. In the earliest phases of the collapse of a protostar a disc forms around the young star and such discs are observed for the first several million years of a star's life. It is within these…
Particle acceleration at plasma shocks appears to be ubiquitous in the universe, spanning systems in the heliosphere, supernova remnants, and relativistic jets in distant active galaxies and gamma-ray bursts. This review addresses some of…