1998/05/01 by Kazuyuki Omukai, K. Omukai, Ryoichi Nishi +5 · 1 citation
Chemistry · Physics and Astronomy · #Advanced Physical and Chemical Molecular Interactions #Astrophysics and Star Formation Studies #Contraction (grammar) #Fragmentation (computing) #Fullerene Chemistry and Applications #Molecular cloud #Opacity #Radiative cooling #Radiative transfer #astro-ph
paper · pdf · doi:10.1143/ptp.99.747
published as Prog.Theor.Phys. 99 (1998) 747-761 · 13 pages, 8 Postscript figures, uses ptptex
openalex publication_date 1998/05/01 · arxiv created 1998/09/18 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The contraction processes of metal-free molecular clouds of starlike mass (or cloud cores) are investigated. We calculate radiative transfer of the H2 lines and examine quasi-static contraction with radiative cooling. Comparing two time-scales, the free-fall time tff and the time-scale of quasi-static contraction tqsc (∼tcool, the cooling time) of these cores, we find that the ratio of the two time-scales tff/tqsc, i.e., the efficiency of cooling, becomes larger with contraction even under the existence of cold and opaque envelopes. In particular, for fragments of primordial filamentary clouds, for which tff ∼tqsc at the fragmentation epoch, they collapse dynamically in the free-fall time-scale. This efficiency of cooling is unique to line cooling.