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Masers as chemical probes of star-forming regions

Published online by Cambridge University Press:  25 May 2016

Karl M. Menten
Karl M. Menten*
Affiliation:
Harvard-Smithsonian Center for Astrophysics 60 Garden Street, Cambridge MA 02138, USA

Abstract

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Maser emission from the OH, H2O, and CH3OH molecules is found toward hundreds of molecular cloud cores with recent and on-going star formation. The often very high intensities of the observed emission imply substantial abundances of the maser molecules, which are difficult or impossible to explain with ion-molecule gas phase chemistry. We summarize relevant observations which show that OH and Class II CH3OH masers form in the envelopes of ultracompact HII regions in which the high abundances of these molecules are produced by evaporation of methanol and water from icy dust grain mantles. In contrast, H2O masers form in outflows from protostellar objects, where high H2O abundances are produced by endothermic neutral-neutral reactions in hot postshock gas. Finally, we briefly discuss Class I CH3OH masers, which also arise in interstellar outflows.

Type
Star Formation
Information
Symposium - International Astronomical Union , Volume 178: Molecules in Astrophysics: Probes and Processes , 1997 , pp. 163 - 172
Copyright
Copyright © Kluwer 1997 

References

Alcolea, J., Menten, K. M., Moran, J. M., Reid, M. J. 1992, in Astrophysical Masers, ed. Clegg, A. W. & Nedoluha, G. E. (Springer, Berlin), p. 225.Google Scholar
Allamandola, L. J., Sandford, S. A., Tielens, A. G. G. M., Herbst, T. M. 1992, ApJ, 399, 134.CrossRefGoogle Scholar
Bloemhof, E. E., Reid, M. J., Moran, J. M. 1992, ApJ, 397, 500.CrossRefGoogle Scholar
Cernicharo, J., Thum, C., Hein, H., John, D., Garcia, P., Mattioco, F. 1990, A&A, 231, L15.Google Scholar
Cesaroni, R., Walmsley, C. M. 1991, A&A, 241, 537.Google Scholar
Charnley, S. B., Tielens, A. G. G. M., Millar, T. J., 1992, ApJ, 399, L71.Google Scholar
Clegg, A. W., Nedoluha, G. E., eds. 1993, Astrophysical Masers (Springer, Berlin).Google Scholar
Cohen, R. J. 1989, Rep. Prog. Phys., 52, 881.Google Scholar
Cragg, D. M., Johns, K. P., Godfrey, P. D., Brown, R. D. 1992, MNRAS, 259, 203.Google Scholar
Davis, C. J., Smith, M. D. 1996, A&A, 310, 961.Google Scholar
Elitzur, M. 1991, Astronomical Masers, (Kluwer, Dordrecht).Google Scholar
Elitzur, M., de Jong, T. 1978, A&A, 67, 323.Google Scholar
Elitzur, M., Hollenbach, D. J., McKee, C. F. 1989, ApJ, 346, 983.Google Scholar
Genzel, R., Reid, M. J., Moran, J. M., Downes, D. 1979, ApJ, 244, 884.CrossRefGoogle Scholar
Grim, R. J. A., Baas, F., Geballe, T. R., Greenberg, J. M., Schutte, W. 1991, A&A, 243, 473.Google Scholar
Gwinn, C. R., Moran, J. M., Reid, M. J. 1992, ApJ, 393, 149.Google Scholar
Hartquist, T. W., Menten, K. M., Lepp, S., Dalgarno, A. 1995, MNRAS, 272, 184.CrossRefGoogle Scholar
Johnston, K. J., Gaume, R., Stolovy, S., Wilson, T. L., Walmsley, C. M., Menten, K. M. 1992, ApJ, 385, 232.CrossRefGoogle Scholar
Liechti, S., Walmsley, C.M. 1996, A&A, in press.Google Scholar
Mehringer, D. M., Menten, K. M. 1996, ApJ 474, 346.CrossRefGoogle Scholar
Melnick, G. J., Menten, K. M., Phillips, T. G., Hunter, T. 1993, ApJ, 416, L37.Google Scholar
Menten, K. M. 1991, in Skylines (Proc. Third Haystack Observatory Meeting), ed. Haschick, A. D. & Ho, P. T. P. (ASP, San Francisco), p. 119.Google Scholar
Menten, K. M., Johnston, K. J., Wilson, T. L., Walmsley, C. M., Mauersberger, R., Henkel, C. 1985, ApJ, 293, L83.Google Scholar
Menten, K. M., Melnick, G. J., Phillips, T. G. 1990a, ApJ, 350, L41.Google Scholar
Menten, K. M., Melnick, G. J., Phillips, T. G., Neufeld, D. A. 1990b, ApJ, 363, L27.CrossRefGoogle Scholar
Menten, K. M., Reid, M. J., Pratap, P., Moran, J. M., Wilson, T. L. 1992, ApJ, 401, L39.Google Scholar
Menten, K. M., Walmsley, C. M., Henkel, C., Wilson, T. L. 1986, A&A, 157, 318.Google Scholar
Moran, J. M. 1994, in The Structure and Content of Molecular Clouds, ed. Wilson, T. L. & Johnston, K. J. (Springer, Berlin), p. 89.Google Scholar
Moran, J. M., Ho, P. T. P. 1994, Proc. SPIE, 2200, Amplitude and Intensity Spatial Interferometry II, ed. Breckinridge, J. B., p. 335.Google Scholar
Neufeld, D. A., Melnick, G. J. 1991, ApJ, 368, 215.Google Scholar
Plambeck, R. L., Menten, K. M. 1990, ApJ, 364, 555.Google Scholar
Reid, M. J., Argon, A. L., Masson, C. R., Menten, K. M., Moran, J. M. 1995, ApJ, 443, 238.CrossRefGoogle Scholar
Reid, M. J., Moran, J. M. 1988, in Galactic and Extragalactic Radio Astronomy, eds. Verschuur, G. & Kellermann, K. I. (Springer, Berlin), p. 225.Google Scholar
Skinner, C. J., Tielens, A. G. G. M., Barlow, M. J., Justtanont, K. 1992, ApJ, 399, L79.Google Scholar
Turner, J. L., Welch, W. J. 1984, ApJ, 287, L81.Google Scholar
van Dishoeck, E. F., Helmich, F. P. 1996, A&A, 315, ∗∗∗ .Google Scholar
Watson, W. D. 1993, in The Structure and Content of Molecular Clouds, eds. Wilson, T. L. & Johnston, K. J. (Springer, Berlin), p. 109.Google Scholar
Wilson, T. L., Johnston, K. J., Mauersberger, R. 1991, A&A, 251, 220.Google Scholar
Wilson, T. L., Walmsley, C. M., Baudry, A. 1990, A&A, 231, 159.Google Scholar