Year: 1998
Type: article
Abstract: 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.
Source: Progress of Theoretical Physics
DOI: 10.1143/ptp.99.747
Authors: K. Omukai, R. Nishi, H. Uehara, H. Susa
Institutions: Kyoto University, University of Tsukuba
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2145165931