Dichotomy in the Dynamical Status of Massive Cores in Orion - AstrophysicsReport as inadecuate

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Abstract: To study the evolution of high mass cores, we have searched for evidence ofcollapse motions in a large sample of starless cores in the Orion molecularcloud. We used the Caltech Submillimeter Observatory telescope to obtainspectra of the optically thin \H13CO+ and optically thick \HCO+ highdensity tracer molecules in 27 cores with masses $>$ 1 \Ms. The red- andblue-asymmetries seen in the line profiles of the optically thick line withrespect to the optically thin line indicate that 2-3 of these cores are notstatic. We detect evidence for infall inward motions in 9 cores and outwardmotions for 10 cores, suggesting a dichotomy in the kinematic state of thenon-static cores in this sample. Our results provide an important observationalconstraint on the fraction of collapsing inward motions versus non-collapsingre-expanding cores for comparison with model simulations.

Author: T. velusamy, R. Peng, D. Li, P. F. Goldsmith, William D. Langer

Source: https://arxiv.org/


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