Hostname: page-component-586b7cd67f-l7hp2 Total loading time: 0 Render date: 2024-12-01T02:46:12.627Z Has data issue: false hasContentIssue false

MagnetoHydrodynamic shock waves in molecular clouds

Published online by Cambridge University Press:  03 August 2017

B. T. Draine*
Affiliation:
Princeton University Observatory, Peyton Hall, Princeton NJ 08544, U.S.A.

Abstract

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.

The fluid dynamics of MHD shock waves in magnetized molecular gas is reviewed. The different types of shock solutions, and the circumstances under which the different types occur, are delineated. Current theoretical work on C- and J-type shocks, and on the stability of C-type shocks, is briefly described. Observations of the line emission from MHD shocks in different regions appear to be in conflict with theoretical expectations for single, plane-parallel shocks. Replacement of plane-parallel shocks by bow shocks may help reconcile theory and observation, but it is also possible that the observed shocks may not be “steady”, or that theoretical models have omitted some important physics.

Type
Shocks and Instabilities
Copyright
Copyright © Kluwer 1991 

References

Bally, J. 1990, private communication.Google Scholar
Beichman, C. A. 1990, private communication.Google Scholar
Brand, P. W. J. L., Moorhouse, A., Burton, M. G., Geballe, T. R., Bird, M., and Wade, R. 1988, “Ratios of Molecular Hydrogen Line Intensities in Shocked Gas: Evidence for Cooling Zones”, Ap. J. (Letters), 334, L103L106.CrossRefGoogle Scholar
Brand, P. W. J. L., Toner, M. P., Geballe, T. R., and Webster, A. S. 1989a, “The velocity profile of the 1-0S(1) line of molecular hydrogen at Peak 1 in Orion”, M.N.R.A.S., 237, 10091018.CrossRefGoogle Scholar
Brand, P. W. J. L., Toner, M. P., Geballe, T. R., Webster, A. S., Williams, P. M., and Burton, M. G. 19896, “The constancy of the ratio of the molecular hydrogen lines at 3.8 μm in Orion”, M.N.R.A.S., 236, 929934.CrossRefGoogle Scholar
Burton, M. G., Brand, P. W. J. L., Geballe, T. R., and Webster, A. S. 1989, “Molecular hydrogen line ratios in four regions of shock-excited gas”, M.N.R.A.S., 236, 409423.CrossRefGoogle Scholar
Chernoff, D. F. 1987, “Magnetohydrodynamic Shock Waves in Molecular Clouds”, Ap. J., 312, 143169.CrossRefGoogle Scholar
Chernoff, D. F., Hollenbach, D. J., and McKee, C. F. 1982, “Molecular Shock Waves in the BN-KL Region of Orion”, Ap. J. (Letters), 259, L97L102.CrossRefGoogle Scholar
Chernoff, D. F., and McKee, C. F. 1990, “Shocks in dense molecular clouds”, in Molecular Astrophysics, ed. Hartquist, T. R., (Cambridge: Cambridge Univ. Press), pp. 360373.CrossRefGoogle Scholar
Draine, B. T. 1980, “Interstellar Shock Waves with Magnetic Precursors”, Ap. J., 241, 10211038 (erratum: Ap. J., 246, 1045).CrossRefGoogle Scholar
Draine, B. T. 1986, “Multicomponent, reacting MHD flows”, M.N.R.A.S., 220, 130148.CrossRefGoogle Scholar
Draine, B. T., and Roberge, W. G. 1982, “Origin of the Intense Molecular Line Emission from OMC-1”, Ap. J. (Letters), 259, L9196.CrossRefGoogle Scholar
Draine, B. T., Roberge, W. G., and Dalgarno, A. 1983, “Magnetohydrodynamic Shock Waves in Molecular Clouds”, Ap. J., 264, 485507.CrossRefGoogle Scholar
Hartquist, T. W., Flower, D. R., and Pineau des Forets, G. 1990, “Shock chemistry in diffuse clouds”, in Molecular Astrophysics, ed. Hartquist, T. R., (Cambridge: Cambridge Univ. Press), pp. 99112.CrossRefGoogle Scholar
Heiles, C. E. 1991, this volume.Google Scholar
Hollenbach, D. J., Chernoff, D. F., and McKee, C. F. 1989, “Infrared diagnostics of interstellar shocks”, in Infrared Spectroscopy in Astronomy, ed. Kaldeich, B. H. (Noordwijk: ESA Publications Division), pp. 245258.Google Scholar
Moorhouse, A., Brand, P. W. J. L., Geballe, T. R., and Burton, M. G., “Velocity profiles of high-excitation molecular hydrogen lines”, M.N.R.A.S., 242, 8891.CrossRefGoogle Scholar
Mullan, D. J. 1971, “The structure of transverse hydromagnetic shocks in regions of low ionization”, M.N.R.A.S., 153, 145170.CrossRefGoogle Scholar
Roberge, W. G., and Draine, B. T. 1990, “A New Class of Solutions for Interstellar MHD Shock Waves”, Ap. J., 350, 700721.CrossRefGoogle Scholar
Shull, J. M., and Draine, B. T. 1987, “The Physics of Interstellar Shock Waves”, in Interstellar Processes, ed. Hollenbach, D. and Thronson, H. (Dordrecht: Reidel), 283319.CrossRefGoogle Scholar
Smith, M. D., and Brand, P. W. J. L. 1990a, “Cool C-shocks and high-velocity flows in molecular clouds”, M.N.R.A.S., 242, 495504.CrossRefGoogle Scholar
Smith, M. D., and Brand, P. W. J. L. 1990b, “H2 profiles of C-type bow shocks”, M.N.R.A.S., 245, 108118.CrossRefGoogle Scholar
Smith, M. D., Brand, P. W. J. L., and Moorhouse, A. 1990, “Bow shocks in molecular clouds: H2 line strengths”, M.N.R.A.S., submitted.CrossRefGoogle Scholar
Wardle, M. 1990a, “The stability of magnetohydrodynamic shock waves in molecular clouds”, M.N.R.A.S., in press.Google Scholar
Wardle, M. 19906, “The instability of radiative C-type shock waves”, M.N.R.A.S., submitted.Google Scholar
Wardle, M. 1991, in preparation.Google Scholar
Wardle, M., and Draine, B. T. 1987, “Oblique Magnetohydrodynamic Shock Waves in Molecular Clouds”, Ap. J., 321, 321333.CrossRefGoogle Scholar