2003/11/01 by P. Hennebelle · 9 citations
Physics and Astronomy · #Astro and Planetary Science #Astrophysics and Star Formation Studies #Classical mechanics #Isothermal process #Magnetic field #Mechanics #Physics #Prolate spheroid #Quantum mechanics #Statistical physics #Stellar, planetary, and galactic studies #Thermal #Thermodynamics #astro-ph
paper · pdf · doi:10.1051/0004-6361:20031183
published in Astronomy and Astrophysics 411(2), 9-20 (EDP Sciences) · accepted for publication in A&A
openalex publication_date 2003/11/01 · arxiv created 2003/11/10 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We propose an extension of the semi-analytical solutions derived by Lin et al. ([CITE]) describing the two-dimensional homologous collapse of a self-gravitating rotating cloud having uniform density and spheroidal shape, which includes magnetic field (with important restrictions) and thermal pressure. The evolution of the cloud is reduced to three time-dependent ordinary equations allowing one to conduct a quick and preliminary investigation of the cloud dynamics during the precollapse phase, for a wide range of parameters. We apply our model to the collapse of a rotating and magnetized oblate and prolate isothermal core. Hydrodynamical numerical simulations are performed and comparison with the semi-analytical solutions is discussed. Under the assumption that all cores are similar, an apparent cloud axis ratio distribution is calculated from the sequence of successive evolutionary states for each of a large set of initial conditions. The comparison with the observational distribution of the starless dense cores belonging to the catalog of Jijina et al. ([CITE]) shows a good agreement for the rotating and initially prolate cores (aspect ratio 0.5) permeated by an helical magnetic field (G for a density of 104 cm-3).