Hostname: page-component-cd9895bd7-dk4vv Total loading time: 0 Render date: 2024-12-25T16:49:11.557Z Has data issue: false hasContentIssue false
  • English
  • Français

Molecular Clouds

Published online by Cambridge University Press:  14 August 2015

P. Thaddeus
P. Thaddeus*
Affiliation:
Goddard Institute for Space Studies, New York City

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.

To attempt to understand star formation without knowing the physical state of the dense interstellar molecular gas from which stars are made is an almost impossible task. Star formation has developed late as a branch of astrophysics largely for lack of observational data, and in particular, has lagged badly behind the study of the atomic and ionized components of the interstellar gas because spectroscopic techniques which work well at low density have an unfortunate tendency to fail when the density is high. Optical spectroscopy, which has been applied to the interstellar medium for over 70 years, has made little progress in regions of high density because of obscuration, and the same is true a fortiori of spacecraft spectroscopy in the UV; radio 21-cm and recombination line observations, although unhampered by obscuration, are unsatisfactory because the dense condensations are almost entirely molecular in composition.

Type
Research Article
Information
Symposium - International Astronomical Union , Volume 75: Star Formation , 1977 , pp. 37 - 54
Copyright
Copyright © Reidel 1977 

References

Baker, P.L., 1976, Astron. Astrophys. 50, 327.Google Scholar
Baran, G. 1976, Private communication.Google Scholar
Blaauw, A. 1964, Ann Rev. Astron. and Astrophys. 2, 213.Google Scholar
Blair, G.N. Jr. 1976, Unpublished , University of Texas.Google Scholar
Blitz, L. 1976, Private communication.Google Scholar
Brown, R.L., Gammon, R.H., Knapp, G.R., and Balick, B. 1974, Astrophys. J. 192, 607.Google Scholar
Brown, R.L., and Zuckerman, B. 1975, Astrophys. J. (Letters) 202, L125.Google Scholar
Chaisson, E.J. 1975, Astrophys. J. (Letters) 197, L65.Google Scholar
Chaisson, E.J., and Beichman, C.A. 1975, Astrophys. J. (Letters) 199, L39.Google Scholar
Chin, G. 1977, Unpublished , Columbia University.Google Scholar
Clark, F.O., and Johnson, D.R. 1974, Astrophys. J. (Letters) 191, L87.Google Scholar
Cong, H.-I. 1977, Unpublished , Columbia University.Google Scholar
Cong, H.-I., Lada, C.J., Elmegreen, B.G., and Thaddeus, P. 1977, in preparation.Google Scholar
Crutcher, R.M., Evans, N.J., Troland, T., and Heiles, C. 1975, Astrophys. J. 198, 91.Google Scholar
Dickman, R.L. 1975, Astrophys. J. 202, 50.Google Scholar
Dickman, R.L. 1976, Unpublished , Columbia University.Google Scholar
Dieter, N.H. 1973, Astrophys. J. 183, 449.Google Scholar
Elmegreen, B.G., and Lada, C.J. 1976, Astron. J. 81, 1089.Google Scholar
Elmegreen, B.G., and Lada, C.J. 1977, to be published.Google Scholar
Emerson, J.P., Furness, I., and Jennings, R.E. 1975, Mon. Not. Roy. Astron. Soc. 172, 411.Google Scholar
Encrenaz, P.J. 1974, Astrophys. J. (Letters) 189, L135.Google Scholar
Encrenaz, P.J., Falgarone, E., and Lucas, R. 1975, Astron. Astrophys. 44, 73.Google Scholar
Encrenaz, P.J., Wannier, P.G., Jefferts, K.B., Penzias, A.A., and Wilson, R.W. 1973, Astrophys. J. (Letters) 186, L77.Google Scholar
Evans, N.J., Zuckerman, B., Sato, T., and Morris, G. 1975, Astrophys. J. 199, 383.Google Scholar
Fazio, G.G., Wright, E.L., Zelik, M., and Low, F.J. 1976, Astrophys. J. (Letters) 206, L165.Google Scholar
Gautier, T.N., Fink, U., Treffers, R., and Larson, H.P. 1976, Astrophys. J. (Letters) 207, L129.Google Scholar
Guélin, M., Langer, W., Snell, R.N., and Wootten, H.A. 1977, to be published.Google Scholar
Grasdalen, G.L., Strom, K.M., and Strom, S.E. 1973, Astrophys. J. (Letters) 184, L53.Google Scholar
Heiles, C. 1976, Ann. Rev. Astron. Astrophys. 14, 1.Google Scholar
Heiles, C., and Jenkins, E.B. 1976, Astron. Astrophys. 46, 333.Google Scholar
Herbst, E., and Klemperer, W. 1973, Astrophys. J. 185, 505.Google Scholar
Hollis, J.M., Snyder, L.E., Lovas, F.J., and Buhl, D. 1976, Astrophys. J. (Letters) 209, L83.Google Scholar
Jenkins, E., and Shaya, E. 1977, to be published.Google Scholar
Kislyakov, A.G., and Turner, B.E. 1976, Astron. J. 81, 302.Google Scholar
Knapp, G.R., Brown, R.L., and Kuiper, T.B.H. 1975, Astrophys. J. 196, 167.Google Scholar
Kutner, M.L., Evans, N.J., and Tucker, K.D. 1976, Astrophys. J. 209, 452.Google Scholar
Kutner, M.L., Tucker, K.D., Chin, G., and Thaddeus, P. 1977, Astrophys. J. (in press).Google Scholar
Lada, C.J. 1976, Astrophys. J. Supp. 32, 603.Google Scholar
Langer, W. 1976, Astrophys. J. 206, 699.Google Scholar
Leung, C.M., and Liszt, H.S. 1976, Astrophys. J. 208, 732.Google Scholar
Linke, R.A., and Wannier, P.G. 1974, Astrophys. J. (Letters) 193, L41.Google Scholar
Liszt, H.S. 1973, Unpublished , Princeton University.Google Scholar
Loren, R.B. 1975, Unpublished , University of Texas.Google Scholar
Loren, R.B., Vanden Bout, P.A., and Davis, J.H. 1973, Astrophys. J. (Letters), 185, L67.Google Scholar
Mahoney, M.J., McCutcheon, W.H., and Shuter, W.L.H. 1976, Astron. J. 81, 508.Google Scholar
Martin, R.N., and Barrett, A.H. 1975, Astrophys. J. (Letters) 202, L83.Google Scholar
Milman, A. S., Knapp, G.R., Kerr, F.J., Knapp, S.L., and Wilson, W.J. 1975, Astron. J. 80, 93.Google Scholar
Milman, A. S., Knapp, G.R., Knapp, S.L., and Wilson, W.J. 1975, Astron. J. 80, 101.Google Scholar
Morris, M., Zuckerman, B., Palmer, P., and Turner, B.E. 1973, Astrophys. J. 186, 501.Google Scholar
Myers, P.C. 1973, Astrophys. J. Supp. No. 229 26, 83.Google Scholar
Myers, P.C. 1975, Astrophys. J. 198, 331.Google Scholar
Myers, P.C., and Ho, P.T.P. 1975, Astrophys. J. (Letters) 202, L25.Google Scholar
Penzias, A.A. 1975, in “Atomic and Molecular Physics and the Interstellar Matter” Les Houches Summer School of Theoretical Physics, North-Holland Pub. Co.Google Scholar
Penzias, A.A., Jefferts, K.B., and Wilson, R.W. 1971, Astrophys. J. 165, 229.Google Scholar
Phillips, T.G. 1976, Private communication.Google Scholar
Phillips, T.G., and Huggins, P.J. 1976, Astrophys. J. 211, 798.Google Scholar
Phillips, T.G., Jefferts, K.B., and Wannier, P.G. 1973, Astrophys. J. (Letters) 186, L19.Google Scholar
Sandqvist, Aa, and Lindroos, K.P. 1976, Astron. Astrophys. 53, 179.Google Scholar
Sargent, A.I. 1976, Private communication.Google Scholar
Simon, M., Righini, G., Joyce, R.R., and Gezari, D.Y. 1973, Astrophys. J. (Letters) 186, L127.Google Scholar
Snyder, L.E., and Hollis, J.M. 1976, Astrophys. J. (Letters) 204, L139.Google Scholar
Spitzer, L. Jr., Cochran, W.D., and Hirshfeld, A. 1974, Astrophys. J. Supp. 28, 373.Google Scholar
Strom, K.M., Strom, S.E., Carrasco, L., and Vrba, F.J. 1975, Astrophys. J. 196, 489.Google Scholar
Tsuji, T. 1964, Ann. Tokyo Astron. Obs. 9, 1.Google Scholar
Tucker, K.D., Dickman, R.L., Encrenaz, P.J., and Kutner, M.L. 1976, Astrophys. J. 210, 679.Google Scholar
Tucker, K.D., Kutner, M.L., and Thaddeus, P. 1974, Astrophys. J. (Letters) 193, L115.Google Scholar
Turner, B.E., and Verschuur, G.L. 1970, Astrophys. J. 162, 341.Google Scholar
Verschuur, G.L. 1974, in Galactic and Extragalactic Radio Astronomy ed. Verschuur, G.L. and Kellerman, K.I. (Springer-Verlag, New York), p. 179.Google Scholar
Vrba, F.J., Strom, K.M., Strom, S.E., and Grasdalen, G.L. 1975, Astrophys. J. 197, 77.Google Scholar
Wannier, P.G., Penzias, A.A., Linke, R.A., and Wilson, R.W. 1976, Astrophys. J. 204, 26.Google Scholar
Watson, W.D., and Salpeter, E.E. 1972, Astrophys. J. 175, 659.Google Scholar
Westbrook, W.E., Werner, M.W., Elias, J.H., Gezari, D.Y., Hauser, M.G., Lo, K.Y., and Neugebauer, G. 1976, Astrophys. J. 209, 94.Google Scholar
Wilson, W.J., Schwartz, P.R., Epstein, E.E., Johnson, W.A., Etcheverry, R.D., Mori, T.T., Berry, G.G., and Dyson, H.B. 1974, Astrophys. J. 191, 357.Google Scholar
Zuckerman, B., and Palmer, P. 1974, Ann. Rev. Astron. Astrophys. 12, 279.Google Scholar
Zuckerman, B., and Palmer, P. 1975, Astrophys. J. (Letters) 199. L35.Google Scholar