1996/08/02 by Barbara S. Ryden · 9 citations
Chemistry · Materials Science · Physics and Astronomy · #Advanced Physical and Chemical Molecular Interactions #Chemical and Physical Properties of Materials #Material Dynamics and Properties #astro-ph
paper · pdf · doi:10.1086/178010
26 pages (LaTeX) including 8 postscript figures; to appear in ApJ
arxiv created 1996/08/02 · openalex publication_date 1996/11/10 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/01
The shapes of isolated Bok globules and embedded dense cores of molecular clouds are analyzed using a nonparametric method, under the alternate hypotheses that they are randomly oriented prolate objects or that they are randomly oriented oblate objects. In all cases, the prolate hypothesis gives a better fit to the data. If Bok globules are oblate, they must be very flat; the average axis ratio is b/a = 0.3, and few or no globules can have b/a > 0.7. If Bok globules are prolate, then the mean axis ratio is b/a = 0.5. For most data samples of dense cores, the randomly-oriented oblate hypothesis can be rejected at the 99% confidence level. If the dense cores are prolate, their mean axis ratio is approximately 0.4 to 0.5. Dense cores are significantly different in shape from the clouds in which they are embedded; clouds have flatter apparent shapes, and are inconsistent with a population of randomly oriented axisymmetric objects.