相关论文: Cold Dark Clouds: The Initial Conditions for Star …
Context: Infrared dark clouds are the coldest and densest portions of giant molecular clouds. The most massive ones represent some of the most likely birthplaces for the next generation of massive stars in the Milky Way. Because a strong…
Pre-stellar cores represent the initial conditions of star formation. Although these initial conditions in nearby low-mass star-forming regions have been investigated in detail, such initial conditions remain vastly unexplored for massive…
We investigate, through a series of numerical calculations, the evolution of dense cores that are accreting external gas up to and beyond the point of star formation. Our model clouds are spherical, unmagnetized configurations with fixed…
Modelling of Extreme Scattering Events suggests that the Galaxy's dark matter is an undetected population of cold, AU-sized, planetary-mass gas clouds. None of the direct observational constraints on this picture -- thermal/non-thermal…
Super Star Clusters are one of the most extreme star forming environments in the universe, and the most massive and dense of these may be proto globular clusters. Like individual massive stars, the earliest stages of super star cluster…
In the currently-accepted model for star formation out of the interstellar gas in galaxies, the basic construction material is assumed to be large clouds of atomic hydrogen (HI). These clouds are thought to form higher-density complexes of…
Although the basic physics of star formation is classical, numerical simulations have yielded essential insights into how stars form. They show that star formation is a highly nonuniform runaway process characterized by the emergence of…
It has been known for more than 30 years that star formation in giant molecular clouds (GMCs) is slow, in the sense that only ~1% of the gas forms stars every free-fall time. This result is entirely independent of any particular model of…
The physical conditions in molecular clouds control the nature and rate of star formation, with consequences for planet formation and galaxy evolution. The focus of this review is on the conditions that characterize regions of star…
Infrared-dark clouds (IRDCs) are the precursors to massive stars and stellar clusters. G011.11-0.12 is a well-studied filamentary IRDC, though, to date, the absence of far-infrared data with sufficient spatial resolution has limited the…
The first phase of stellar evolution in the history of the universe may be Dark Stars, powered by dark matter heating rather than by fusion. Weakly interacting massive particles, which are their own antiparticles, can annihilate and provide…
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…
Stars form from the gravitational collapse of dense molecular cloud cores. In the protostellar phase, mass accretes from the core onto a protostar, likely through an accretion disk, and it is during this phase that the initial masses of…
The dense molecular cloud cores that form stars, like other self-gravitating objects, undergo bulk oscillations. Just at the point of gravitational instability, their fundamental oscillation mode has zero frequency. We study, using…
We summarize some of the results obtained from Herschel surveys of the nearby star forming regions and the Galactic plane. We show that in the nearby star forming regions the starless core spatial surface density distribution is very…
To constrain the nature of the very first stars, we investigate the collapse and fragmentation of primordial, metal-free gas clouds. We explore the physics of primordial star formation by means of three-dimensional simulations of the dark…
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…
We present a model of the interaction of interstellar dust grains with a stellar environment, that predicts the distribution of interstellar dust grains in the size range between $0.1 {\rm \mu m}$ and $1 {\rm \mu m}$ around a star for the…
Optically thin cooling gas at most temperatures above 30K will make condensations by pressure pushing material into cool dense regions. This works without gravity. Cooling condensations will flatten and become planar/similarity solutions.…
(Abridged) The formation of molecular clouds (MCs) from the diffuse interstellar gas appears to be a necessary step for star formation, as young stars invariably occur within them. However, the mechanisms controlling the formation of MCs…