Hostname: page-component-78c5997874-v9fdk Total loading time: 0 Render date: 2024-11-14T06:46:36.528Z Has data issue: false hasContentIssue false
  • English
  • Français

Abundance variations of tracers and their effects on our determination of molecular cloud structure

Published online by Cambridge University Press:  03 August 2017

Paul F. Goldsmith
Paul F. Goldsmith*
Affiliation:
Five College Radio Astronomy Observatory, Department of Physics and Astronomy, University of Massachusetts, Amherst MA 01003

Extract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Our understanding of the molecular phase of the interstellar medium is critically dependent on use of various lines from different molecular species to trace this dense material. As our knowledge of molecular clouds becomes more refined, and we pursue in detail issues of molecular cloud structure, stability, and how star formation depends on and affects the molecular gas, it is appropriate to examine the basis by which we determine the morphology of clouds, their density, and other key parameters. This is obviously a major undertaking, well beyond the scope of the short presentation at this conference, so I will concentrate on one very basic, but critical issue, which is that of abundance variations of tracers of density and molecular column density which are widely used to delineate the denser portions of all types of molecular clouds. In this summary, I will first highlight some of the apparent indications of significant variations of abundance within individual clouds, as a way of indicating some potential dangers and the importance of the molecular tracer selected. I will also briefly suggest how such variations may be themselves important diagnostics of cloud structure and evolution.

Type
Chemistry
Information
Symposium - International Astronomical Union , Volume 147: Fragmentation of Molecular Clouds and Star Formation , 1991 , pp. 177 - 181
Copyright
Copyright © Kluwer 1991 

References

Arquilla, R., and Goldsmith, P.F. 1985, Ap.J. 297, 436.CrossRefGoogle Scholar
Blake, G.A., Sutton, E.C., Masson, C.R., and Phillips, T.G. 1987, Ap.J., 315, 621.Google Scholar
Dickman, R.L. 1978, Ap.J. Suppl., 37, 407.Google Scholar
Federman, S.R., Huntress, W.T. Jr., and Prasad, S.S. 1990, Ap.J., 354, 504.Google Scholar
Frerking, M.A., Langer, W.D., and Wilson, R.W. 1982, Ap.J., 262, 590.Google Scholar
Goldsmith, P.F., Langer, W.D., Carlson, E.R., and Wilson, R.W. 1980, in Proc. IAU Symp. 87, Andrew, B., ed. Dordrecht: Reidel, p. 417.Google Scholar
Goldsmith, P.F., Snell, R.L., Hasegawa, T., and Ukita, N. 1987, Ap.J., 314, 525.Google Scholar
Goldsmith, P.F., Margulis, M., Snell, R.L., and Fukui, Y. 1990, in preparation.Google Scholar
Graedel, T.E., Langer, W.D., and Frerking, M.A. 1982, Ap.J.Suppl., 48, 321.Google Scholar
Irvine, W.M., Goldsmith, P.F., and Hjalmarson, A. 1987, in Interstellar Processes, Thronson, H. and Hollenbach, D., eds. Dordrecht: Reidel, 561.Google Scholar
Irvine, W.M. 1990, in Chemistry and Spectroscopy of Interstellar Molecules, Kaifu, N., ed. Tokyo: University of Tokyo, in press.Google Scholar
Iwata, T., Fukui, Y., and Ogawa, H. 1988, Ap.J., 325, 372.Google Scholar
Johansson, L.E.B. et al. 1984, Astr. Astrophys., 130, 227.Google Scholar
Langer, W.D., Wilson, R.W., Goldsmith, P.F., and Beichman, C.A. 1989, Ap.J., 337, 355.Google Scholar
Lis, D.C., and Goldsmith, P.F. 1989, Ap.J., 337, 704.Google Scholar
Lis, D.C., and Goldsmith, P.F. to appear in Ap.J., 1991.Google Scholar
Minh, Y.C., Irvine, W.M., and Ziurys, L.M. 1988, Ap.J., 334, 175.Google Scholar
Olano, C.A., Walmsley, C.M., and Wilson, T.L. 1988, Astr. Astrophys., 196, 194.Google Scholar
Pineau des Forets, G., Roueff, E., and Flower, D.R. 1989, J. Chem. Soc. Faraday Trans., 2, 85(10), 1665.Google Scholar
Plambeck, R. and Wright, M. 1988, in Molecular Clouds in the Milky Way and External Galaxies, Dickman, R., Snell, R., Young, J., eds. Berlin: Springer, 182.Google Scholar
Swade, D.A. 1989, Ap.J. Suppl., 71, 219; Ap.J., 345, 828.Google Scholar
Vogel, S.N., Genzel, R., and Palmer, P. 1987, Ap.J., 316, 243.Google Scholar
Zhou, S., Evans, N.J. II, and Mundy, L. 1990, Ap.J., 355, 159.Google Scholar