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Dynamical conditions of dense clumps in dark clouds: a strategy for elucidation

Published online by Cambridge University Press:  03 August 2017

Sheo S. Prasad
Sheo S. Prasad*
Affiliation:
Lockheed Palo Alto Research Laboratory 3251 Hanover Street (MC: O/91-20; B255) Palo Alto, CA 94304; USA Departments of Physics and Astronomy University of Southern California Los Angeles, CA 90089-1341; USA

Abstract

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Chemical considerations and simplified dynamical modeling suggest that dark cloud cores may be incessantly evolving such that the time spent at high core densities decreases as the density increases. After reaching a high density, gravitationally contracting dark cloud cores may either form stars or expand to states of lower densities. Cloud mass and initial density are amongst the factors that may control the evolutionary fate of the core. This view is diametrically opposite of the common belief that dense cores may be in near mechanical equilibrium. Mutually consistent end-to-end modeling of the spectral line profiles and intensities is needed to discern the reality.

Type
Velocity Field and Magnetic Field
Information
Symposium - International Astronomical Union , Volume 147: Fragmentation of Molecular Clouds and Star Formation , 1991 , pp. 93 - 99
Copyright
Copyright © Kluwer 1991 

References

Boissé, P. 1990, Astron. Astrophys., 228, 483.Google Scholar
Boland, W., and de Jong, T. 1982, Ap. J., 261, 110.Google Scholar
Chièze, J. P., and Pineau des Forêts, G. 1989, Astron. Astrophys., 221, 89.Google Scholar
Herbst, E., and Leung, C. M. 1986, M. N. R. A. S., 222, 689.Google Scholar
Herbst, E., and Leung, C. M. 1986b, Ap. J., 310, 378.CrossRefGoogle Scholar
Myers, P. C. 1983, Ap. J., 270, 105.Google Scholar
Prasad, S. S. 1987, in Astrochemistry, Proceedings of IAU Symposium 120 (Vardya, M. S. and Tarafdar, S. P., Eds.), p. 259. D. Reidel Publishing Co.Google Scholar
Prasad, S. S., Tarafdar, S. P., Villere, K. R., and Huntress, W. T. Jr., 1987, Interstellar Processes (Hollenbach, D. J. and Thronson, H. A., Eds.) p. 631, D. Reidel Publishing Co. Google Scholar
Prasad, S.S., Heere, K. R., and Tarafdar, S. P. 1990. “Dynamical Evolution and Molecular Abundances of Interstellar Clouds”. To appear in Ap. J. CrossRefGoogle Scholar
Solomon, P. 1990. “Fragmentation and clumpiness in inner-Galaxy giant molecular clouds”. In these Proceedings. Google Scholar
Swade, D. A. 1989, Ap. J., 345, 828.Google Scholar
Tarafdar, S. P., Prasad, S. S., Huntress, W. T. Jr., Villere, K. R., and Black, D. C. 1985, Ap. J., 289, 220.CrossRefGoogle Scholar
Tauber, J. A., and Goldsmith, P. F. 1990, Ap. J., 356, 163.Google Scholar
Thaddeus, P. 1990. “The Hierarchial structure of molecular clouds (gas and dust). Connection between observations in our galaxy and nearby galaxies.” In these Proceedings. Google Scholar
Villere, K. R., and Black, D. C. 1982, Bull. Am. Astron. Soc., 14, 970.Google Scholar
Williams, D. A. 1986, Quart. J. Roy. Astr. Soc., 27, 64.Google Scholar
Williams, D. A. 1987 in Rate Coefficients in Astrochemistry, (Millars, T. J. and Williams, D. A., Eds.), Kluwer Academic Publishers, p. 281.Google Scholar
Williams, D. A., and Hartquist, T. W. 1984, M. N. R. A. S., 210, 141.Google Scholar
Zuckerman, B., and Palmer, P. 1974, Ann. Rev. Astron. Astrophys., 12, 279.CrossRefGoogle Scholar