Related papers: Evolution of Primordial Protostellar Clouds --- Qu…
The evolution of collapsing metal free protostellar clouds is investigated for various masses and initial conditions. We perform hydrodynamical calculations for spherically symmetric clouds taking account of radiative transfer of the…
The thermal and chemical evolution of gravitationally collapsing protostellar clouds is investigated, focusing attention on their dependence on metallicity. Calculations are carried out for a range of metallicities spanning the local…
The evolution of radiation emitted during the dynamical collapse of metal-free protostellar clouds is investigated within a spherically symmetric hydrodynamical scheme that includes the transfer of radiation and the chemistry of the…
We present an idealized, spherical model of the evolution of a magnetized molecular cloud due to ambipolar diffusion. This model allows us to follow the quasi-static evolution of the cloud's core prior to collapse and the subsequent…
In the context of star formation through fragmentation of an extremely metal-deficient protogalactic cloud, the gravitational collapse of filamentary gas clouds is explored with 1D numerical hydrodynamics coupled with non-equilibrium…
The collapse of dense cores with different metallicities is studied by hydrodynamical calculations coupled with detailed chemical and radiative processes. For this purpose, we construct a simple chemical network with non-equilibrium…
Many questions in physical cosmology regarding the thermal history of the intergalactic medium, chemical enrichment, reionization, etc. are thought to be intimately related to the nature and evolution of pregalactic structure. In particular…
We study the thermal evolution of primordial star-forming gas clouds using three-dimensional cosmological simulations. We critically examine how assumptions and approximations made in calculating radiative cooling rates affect the dynamics…
We investigate numerically and semi-analytically the collapse of low-mass, rotating prestellar cores. Initially, the cores are in approximate equilibrium with low rotation (the initial ratio of thermal to gravitational energy is $\alpha_0…
Linear analysis of the formation of protostellar cores in planar magnetic interstellar clouds shows that molecular clouds exhibit a preferred length scale for collapse that depends on the mass-to-flux ratio and neutral-ion collision time…
We investigate the thermal and dynamical evolution of primordial gas clouds in the universe after decoupling. Comparing the time-scale of dynamical evolution with that of fragmentation, we can estimate the typical fragmentation scale. We…
Many questions in physical cosmology regarding the thermal history of the intergalactic medium, chemical enrichment, reionization, etc. are thought to be intimately related to the nature and evolution of pregalactic structure. In particular…
Properties of candidate stars, forming out of molecular clouds, depend on the ambient conditions of the parent cloud. We present a series of 2D and 3D simulations of fragmentation of molecular clouds in starburst regions as well as clouds…
A physical model and two-dimensional numerical method for computing the evolution and spectra of protostellar clouds are described. The physical model is based on a system of magneto-gasdynamical equations, including ohmic and ambipolar…
We review recent advances in the analytical and numerical modeling of the star formation rate in molecular clouds and discuss the available observational constraints. We focus on molecular clouds as the fundamental star formation sites,…
We analyze an ensemble of simulated prestellar cores to facilitate interpretation of structure, kinematics, and lifetime of observed cores. While our theory predicts a "characteristic" density for star formation, it also predicts that the…
Dynamical collapse and fragmentation of low-metallicity cloud cores is studied using three-dimensional hydrodynamical calculations, with particular attention devoted whether the cores fragment in the dust-cooling phase or not. The cores…
We present idealized numerical simulations of prestellar gravitational collapse of a moderate initial filamentary perturbation with an additional central ellipsoidal enhancement (a core) considering a uniform, and a stratified background,…
We study the dynamics of a self-gravitating cooling filamentary cloud using a simplified model. We concentrate on the radial distribution and restrict ourselves to quasi-hydrostatic, cylindrically symmetric cooling flows. For a power-law…
We review the properties of low mass dense molecular cloud cores, including starless, prestellar, and Class 0 protostellar cores, as derived from observations. In particular we discuss them in the context of the current debate surrounding…