Related papers: The Physics of Star Cluster Formation and Evolutio…
In this contribution we review our recent numerical work discussing the essential role of the local cluster environment in assembling massive stars. First we show that massive stars are formed from low mass pre-stellar cores and become…
The observed increase in star formation efficiency with average cloud density, from several percent in whole giant molecular clouds to ~30 or more in cluster-forming cores, can be understood as the result of hierarchical cloud structure if…
Within the birth environment of a massive globular cluster, the combination of a luminous young stellar population and a high column density induces a state in which the thermal optical depth and radiation pressure are both appreciable. In…
I review observational studies of the large-scale star formation process in nearby galaxies. A wealth of new multi-wavelength data provide an unprecedented view on the interplay of the interstellar medium and (young) stellar populations on…
Stars form within molecular clouds but our understanding of this fundamental process remains hampered by the complexity of the physics that drives their evolution. We review our observational and theoretical knowledge of molecular clouds…
The process that leads to the formation and early evolution of low-mass stars is in a broad sense well understood theoretically and carefully traced observationally. The largest uncertainties in this framework reside in the poorly known…
Most stars are born in rich young stellar clusters (YSCs) embedded in giant molecular clouds. The most massive stars live out their short lives there, profoundly influencing their natal environments by ionizing HII regions, inflating…
Most formation scenarios of globular clusters assume a molecular cloud as the progenitor of the stellar system. However, it is still unclear, how this cloud is transformed into a star cluster, i.e. how the destructive processes related to…
We use direct N-body simulations of gas embedded star clusters to study the importance of stellar collisions for the formation and mass accretion history of high-mass stars. Our clusters start in virial equilibrium as a mix of gas and…
Stars are forming in our galaxy at a rate of between 1 and 4 solar masses of stars per year. In contrast to elliptical galaxies, which are largely devoid of star formation, star formation is still going on in spiral galaxies because of…
The properties of old globular cluster systems (GCSs) in galaxy halos offer unique insight into the physical processes that conspire to form any generic star cluster, at any epoch. Presented here is a summary of the information obtained…
The realization that most stars form in clusters, raises the question of whether star/planet formation are influenced by the cluster environment. The stellar density in the most prevalent clusters is the key factor here. Whether dominant…
Gas processes affecting star formation are reviewed with an emphasis on gravitational and magnetic instabilities as a source of turbulence. Gravitational instabilities are pervasive in a multi-phase medium, even for sub-threshold column…
This lecture reviews the fundamental physical processes involved in star formation in galaxy interactions and mergers. Interactions and mergers often drive intense starbursts, but the link between interstellar gas physics, large scale…
Galaxies in clusters are gas-deficient and a number of possible explanations for this observation have been advanced, including galaxy-cluster tidal interactions, galaxy harassment, and ISM-ICM gas stripping. In this paper, we use a…
We present a model for the formation of massive ($M > 10 M_\odot$) stars through accretion-induced collisions in the cores of embedded dense stellar clusters. This model circumvents the problem of accreting onto a star whose luminosity is…
Utilizing a series of N-body simulations, we argue that gravitationally bound stellar clusters of modest population evolve very differently from the picture presented by classical dynamical relaxation theory. The system's most massive stars…
We model the formation of high-mass stars, specifying the accretion rate in terms of the instantaneous and final mass of the star, the ambient pressure of the star-forming region and the form of polytropic pressure support of the…
Stellar clusters are critical constituents within galaxies: they are the result of highest-density star formation, and through their spatially and temporally correlated feedback they regulate their host galaxy evolution. We present a novel…
Star formation is enhanced in spiral arms because of a combination of orbit crowding, cloud collisions, and gravitational instabilities. The characteristic mass for the instability is 10^7 Msun in gas and 10^5 Msun in stars, and the…