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Related papers: Cold Dark Clouds: The Initial Conditions for Star …

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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…

Astrophysics of Galaxies · Physics 2015-08-19 A. Giannetti , F. Wyrowski , S. Leurini , J. Urquhart , T. Csengeri , K. M. Menten , L. Bronfman , F. F. S. van der Tak

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…

Solar and Stellar Astrophysics · Physics 2015-06-16 Motahareh Mohammadpour , Steven W. Stahler

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…

Astrophysics · Physics 2015-06-24 Mark Walker , Mark Wardle

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…

Astrophysics · Physics 2009-11-11 Kelsey E. Johnson

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…

Astrophysics · Physics 2007-05-23 Ronald J. Allen

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…

Astrophysics · Physics 2008-11-26 Richard B. Larson

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…

Astrophysics · Physics 2008-11-26 Mark R. Krumholz , Jonathan C. Tan

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…

Astrophysics · Physics 2009-10-31 Neal J. Evans

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…

Cosmology and Nongalactic Astrophysics · Physics 2010-02-17 Paolo Gondolo , Katherine Freese , Douglas Spolyar , Anthony Aguirre , Peter Bodenheimer , Jeremy A. Sellwood , Naoki Yoshida

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…

Astrophysics · Physics 2007-05-23 B. G. Elmegreen , Y. N. Efremov , R. E. Pudritz , H. Zinnecker

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…

Solar and Stellar Astrophysics · Physics 2009-11-13 Steven W. Stahler , Jeffrey J. Yen

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…

Astrophysics of Galaxies · Physics 2015-06-12 Leonardo Testi , Eli Bressert , S. Longmore

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…

Astrophysics · Physics 2009-11-06 Volker Bromm , Paolo S. Coppi , Richard B. Larson

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…

Astrophysics · Physics 2007-05-23 M. Landgraf , P. C. Frisch

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.…

Astrophysics · Physics 2009-11-06 D. Lynden-Bell , C. A. Tout

(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…

Astrophysics · Physics 2007-11-26 P. Hennebelle , M. -M. Mac Low , E. Vazquez-Semadeni