2004/03/31 by Shantanu Basu, Glenn E. Ciolek · 4 citations
Earth and Planetary Sciences · Physics and Astronomy · #Advanced Chemical Physics Studies #Ambipolar diffusion #Astrophysics #Astrophysics and Star Formation Studies #Gravitational collapse #High-pressure geophysics and materials #Mechanics #Molecular cloud #Nuclear physics #Physics #Plasma #Supercritical fluid #Supersonic speed #Thermodynamics #astro-ph
paper · pdf · doi:10.1086/421464
published as Astrophys.J. 607 (2004) L39-L42 · 10 pages, 5 figures, aastex, accepted by ApJ Letters
arxiv created 2004/03/31 · openalex publication_date 2004/04/27 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We extend our earlier work on ambipolar diffusion-induced formation of protostellar cores in isothermal sheetlike magnetic interstellar clouds by studying nonaxisymmetric collapse for the physically interesting regime of magnetically critical and supercritical model clouds (μ 0 ≥ 1, where μ 0 is the initial mass-to-magnetic flux ratio in units of the critical value for gravitational collapse). Cores that form in model simulations are effectively triaxial, with shapes that are typically closer to being oblate rather than prolate. Infall velocities in the critical model (μ 0 = 1) are subsonic; in contrast, a supercritical model (μ 0 = 2) has extended supersonic infall that may be excluded by observations. For the magnetically critical model, ambipolar diffusion forms cores that are supercritical (μ core > 1) and embedded within subcritical envelopes (μ env < 1). Cores in our models have density profiles that eventually merge into a near-uniform background, which is suggestive of observed properties of cloud cores.