Related papers: Star clusters as cosmic ray accelerators
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.…
Massive Star Clusters (SCs) have been proposed as additional contributors to Galactic Cosmic rays (CRs), to overcome the limitations of supernova remnants (SNRs) to reach the highest energy end of the CR spectrum. Thanks to fast mass losses…
Most star complexes are in fact complexes of stars, clusters and gas clouds; term "star complexes" was introduced as general one disregarding the preferential content of a complex. Generally the high rate of star formation in a complex is…
Most star complexes are in fact complexes of stars, clusters and gas clouds; term "star complexes" was introduced as general one disregarding the preferential content of a complex. Generally the high rate of star formation in a complex is…
Observations indicate that most massive stars in the Galaxy appear in groups, called OB associations, where their strong wind activity generates large structures known as superbubbles, inside which the subsequent supernovae (SNe) explode,…
Star clusters form in dense, hierarchically collapsing gas clouds. Bulk kinetic energy is transformed to turbulence with stars forming from cores fed by filaments. In the most compact regions, stellar feedback is least effective in removing…
Massive stars form in clusters within self-gravitating molecular clouds. The size scale of these clusters is sufficiently large that non-thermal, or turbulent, motions of the gas must be taken into account when considering their formation.…
We compute the production of cosmic rays in the dynamical superbubble produced by a cluster of massive stars. Stellar winds, supernova remnants and turbulence are found to accelerate particles so efficiently that the nonlinear feedback of…
Stars form by gravoturbulent fragmentation of interstellar gas clouds. The supersonic turbulence ubiquitously observed in Galactic molecular gas generates strong density fluctuations with gravity taking over in the densest and most massive…
Cosmic rays are energetic nuclei that permeate the entire Galactic disk. Their existence requires the presence of powerful particle accelerators. While Galactic supernova explosions may supply the required energy, there is growing evidence…
In the present-day universe, it appears that most, and perhaps all, massive stars are born in star clusters. It also appears that all star clusters contain stars drawn from an approximately universal initial mass function, so that almost…
Star clusters stand at the intersection of much of modern astrophysics: the interstellar medium, gravitational dynamics, stellar evolution, and cosmology. Here we review observations and theoretical models for the formation, evolution, and…
Non-thermal particles and high-energy radiation can play a role in the dynamical processes in star-forming regions and provide an important piece of the multiwavelength observational picture of their structure and components. Powerful…
Star formation is triggered in essentially three ways: (1) the pressures from existing stars collect and squeeze nearby dense gas into gravitationally unstable configurations, (2) random compression from supersonic turbulence makes new…
Star complexes are the largest globular regions of star formation in galaxies. If there is a spiral density wave, nuclear ring, tidal arm, or other well-defined stellar structure, then gravitational instabilities in the gaseous component…
We propose and investigate a new formation mechanism for globular clusters in which they form within molecular clouds that are formed in the shocked regions created by galactic winds driven by successive supernova explosions shortly after…
Turbulence, self-gravity, and cooling convert most of the interstellar medium into cloudy structures that form stars. Turbulence compresses the gas into clouds directly and it moves pre-existing clouds around passively when there are…
Recent progress in the understanding of star formation is summarized. A consistent picture is emerging where molecular clouds form with turbulent velocity fields and clumpy substructure, imprinted already during their formation. The clouds…
The empirical laws of star formation suggest that galactic-scale gravity is involved, but they do not identify the actual triggering mechanisms for clusters in the final stages. Many other triggering processes satisfy the empirical laws…
Young stars form on a wide range of scales, producing aggregates and clusters with various degrees of gravitational self-binding. The loose aggregates have a hierarchical structure in both space and time that resembles interstellar…