Related papers: Cosmic rays from star clusters
A dense-enough gas-accumulation evolves, over a few Myr of intensifying star formation, to an embedded cluster. If it contains a sufficient amount of mass, O stars form and explosively expel the remaining gas, whereas poorer clusters reduce…
Massive stars drive the evolution of the interstellar medium through their radiative and mechanical energy input. After their birth, they form bubbles of hot gas surrounded by a dense shell. Traditionally, the formation of bubbles is…
Massive stars are mainly found in stellar associations. These massive star clusters occur in the heart of giant molecular clouds. The strong stellar wind activity in these objects generates large bubbles and induces collective effects that…
The currently available empirical evidence on the star formation processes in the extreme, high-pressure environments induced by galaxy encounters, mostly based on high-resolution Hubble Space Telescope imaging observations, strongly…
Planetary nebulae are formed by the matter ejected by low-to-intermediate mass stars (~0.8-8 times the mass of the Sun) towards the end of their lives. As hydrogen and then helium fuel sources run out, stars expand. During these giant…
It is well known that the energy input from massive stars dominates the thermal and mechanical heating of typical regions in the interstellar medium of galaxies. These effects are amplified tremendously in the immediate environment of young…
Little is known about the origins of the giant star clusters known as globular clusters. How can hundreds of thousands of stars form simultaneously in a volume only a few light years across the distance of the sun to its nearest neighbor?…
The identification of major contributors to the locally observed fluxes of Cosmic Rays (CRs) is a prime objective towards the resolution of the long-standing enigma of CRs. We report on a compelling similarity of the energy and radial…
Gamma-ray bursts are the most luminous explosions in the Universe, whose origin and mechanism is the focus of intense interest. They appear connected to supernova remnants from massive stars or the merger of their remnants, and their…
Galaxy clusters form from the infall of dark and baryonic matter at the intersection of cosmic filaments. Most of the baryons are in the form of a hot, magnetized, intracluster plasma detected through its X-ray thermal bremsstrahlung…
We propose a model in which ultra high energy cosmic rays are produced by collisions between neutron stars and axion stars. The acceleration of such a cosmic ray is made by the electric field, $\sim 10^{15} (B/10^{12} {G}) {eV} {cm}^{-1}$,…
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…
Rapid formation of supermassive black holes occurs in dense nuclear star clusters that are initially gas-dominated. Stellar-mass black hole remnants of the most massive cluster sink into the core, where a massive runaway black hole forms as…
Galactic cosmic rays (CR) are particles presumably accelerated in supernova remnant shocks that propagate in the interstellar medium up to the densest parts of molecular clouds, losing energy and their ionisation efficiency because of the…
We propose that the gravitational collapse of supermassive objects ($ M\ga 10^4 M_\odot$), either as relativistic star clusters or as single supermassive stars (which may result from stellar mergers in dense star clusters), could be a…
Cosmic ray acceleration in turbulent interstellar medium is considered. Turbulence is treated as ensemble of moving magnetic traps. We derive equations for particle momentum distribution function that describes acceleration of particles in…
Massive stars blow powerful stellar winds throughout their evolutionary stages from the main sequence to Wolf-Rayet phases. The amount of mechanical energy deposited in the interstellar medium by the wind from a massive star can be…
Star formation is a fundamental process for galactic evolution. One issue over the last several decades has been determining whether star formation is induced by external triggers or is self-regulated in a closed system. The role of an…
Recent observations suggest that gamma ray bursts (GRBs) and their afterglows are produced by highly relativistic jets emitted in core collapse supernova explosions (SNe). The result of the event, probably, is not just a compact object plus…
The origin of cosmic rays in our Galaxy remains a subject of active debate. While supernova remnant shocks are often invoked as the sites of acceleration, it is now widely accepted that the difficulties of such sources in reaching PeV…