Related papers: Variable protostellar mass accretion rates in clou…
The gravitational collapse of a spherical cloud core is investigated by numerical calculations. The initial conditions of the core lie close to the critical Bonnor-Ebert sphere with a central density of \sim 10^4 cm^{-3} in one model…
We present a theoretical model for primordial star formation. First we describe the structure of the initial gas cores as virialized, quasi-hydrostatic objects in accord with recent high resolution numerical studies. The accretion rate can…
We simulate the early stages of the evolution of turbulent, virialized, high-mass protostellar cores, with primary attention to how cores fragment, and whether they form a small or large number of protostars. Our simulations use the Orion…
Protostellar feedback, both radiation and bipolar outflows, dramatically affects the fragmentation and mass accretion from star-forming cores. We use ORION, an adaptive mesh refinement gravito-radiation-hydrodynamics code, to simulate the…
Advanced primordial chemistry networks have been developed to model the collapse of metal-free baryonic gas within the gravitational well of dark matter (DM) halos and its subsequent collapse into Population III stars. At the low densities…
The isothermal dynamical evolution of a clumpy and turbulent molecular cloud region and its fragmentation into a protostellar cluster is investigated numerically. The effect of different initial density and velocity distributions, generated…
We aim to obtain the equations which govern the evolution of the mass density profile of a dense irrotational molecular cloud (MC). Our study is based on the notion of "ensemble of MCs", introduced in our previous work. The MCs are modeled…
Molecular clouds are observed to be turbulent, but the origin of this turbulence is not well understood. As a result, there are two different approaches to simulating molecular clouds, one in which the turbulence is allowed to decay after…
Low-mass stars are generally understood to form by the gravitational collapse of the dense molecular clouds known as starless cores. Continuum observations have not been able to distinguish among the several different hypotheses that…
Protostellar core formation is probably much more dynamic, and magnetic fields are probably much less important, than has been previously assumed in the standard model of low-mass star formation. This revised picture has important…
We present results from the first three-dimensional radiation hydrodynamical calculations to follow the collapse of a molecular cloud core beyond the formation of the stellar core. We find the energy released by the formation of the stellar…
We describe the results of a sequence of simulations of gravitational collapse in a turbulent magnetized region. The parameters are chosen to be representative of molecular cloud material. We find that several protostellar cores and…
Initial conditions for star formation in clusters are estimated for protostars whose masses follow the initial mass function (IMF) from 0.05 to 10 solar masses. Star-forming infall is assumed equally likely to stop at any moment, due to gas…
It has been proposed that some hot molecular cores (HMCs) harbor a young embedded massive star, which heats an infalling envelope and accretes mass at a rate high enough to ``choke off'' an incipient HII region. This class of HMCs would…
We develop a statistical approach for description of dense structures (cores) in molecular clouds that might be progenitors of stars. Our basic assumptions are a core mass-density relationship and a power-law density distribution of these…
The mass growth of protostars is a central element to the determination of fundamental stellar population properties such as the initial mass function. Constraining the accretion history of individual protostars is therefore an important…
Sufficiently massive clumps of molecular gas collapse under self-gravity and fragment to spawn a cluster of stars that have a range of masses. We investigate observationally the early stages of formation of a stellar cluster in a massive…
We present a detailed model for the thermal balance, chemistry, and radiative transfer within quiescent dense molecular cloud cores that contain a central protostar. Large variations in the gas temperature are expected to affect the…
The interstellar medium of galaxies is governed by supersonic turbulence, which likely controls the star formation rate (SFR) and the initial mass function (IMF). Interstellar turbulence is non-universal, with a wide range of Mach numbers,…
We present results from our numerical simulations of collapsing massive molecular cloud cores. These numerical calculations show that massive stars assemble quickly with mass accretion rates exceeding 10^-3 Msol/yr and confirm that the mass…