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Theoretical Simulations of Grain-Surface Processes

Published online by Cambridge University Press:  25 May 2016

Junko Takahashi
Junko Takahashi*
Affiliation:
National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588, Japan

Abstract

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Recent advances in theoretical simulations of grain-surface processes are reviewed. Classical molecular dynamics (MD) computer simulations were performed to investigate the whole process of H2 formation on icy mantles of interstellar dust grains within a single model. Amorphous water ice slabs were generated at 10 K and 70 K as a realistic model surface of dust grains, and then two incident H atoms were successively thrown onto the surface to reproduce the H2 formation process via H + H → H2 on the dust surface. The following fundamental processes were studied in detail; 1) the sticking of H atom onto the grain surface, 2) the diffusion of H atom on the surface, 3) the reaction of two H atoms on the surface, 4) the ejection of H2 from the surface. Then, the formation pumping mechanism of H2 and the chemical desorption mechanism of frozen CO molecules in the vicinity of H2 forming sites on dust grains were also studied.

Type
Part 4. Basic Molecular Processes
Information
Symposium - International Astronomical Union , Volume 197: Astrochemistry: From Molecular Clouds to Planetary Systems , 2000 , pp. 293 - 302
Copyright
Copyright © Astronomical Society of the Pacific 2000 

References

Buch, V. & Devlin, J.P. 1993, J. Chem. Phys., 98, 4195 Google Scholar
Buch, V. & Devlin, J.P. 1994, ApJ, 431, L135 Google Scholar
Buch, V. & Zhang, Q. 1991, ApJ, 379, 647 Google Scholar
Duley, W.W. 1996, MNRAS, 279, 591 Google Scholar
Duley, W.W. & Williams, D.A. 1986, MNRAS, 223, 177 Google Scholar
Duley, W.W. & Williams, D.A. 1993, MNRAS, 260, 37 Google Scholar
Forebrother, A., Fisher, A., & Clary, D.C. 2000, in preparation Google Scholar
Hansen, J.P. & McDonald, I.R. 1986, Theory of Simple Liquids (2nd edition, Academic Press: New York)Google Scholar
Herbst, E. 1995, Annu. Rev. Phys. Chem., 46, 27 Google Scholar
Herzberg, G. 1950, Molecular Spectra and Molecular Structure I. Spectra of Diatomic Molecules (2nd edition, Van Nostrand: New York)Google Scholar
Hollenbach, D. & Salpeter, E.E. 1970, J. Chem. Phys., 53, 79 CrossRefGoogle Scholar
Hunter, D.A. & Watson, W.D. 1978, ApJ, 226, 477 Google Scholar
Jenniskens, P., Blake, D.F., Wilson, M.A., & Pohorille, A. 1995, ApJ, 455, 389 Google Scholar
Jorgensen, W.L. 1982, J. Chem. Phys., 77, 4156 Google Scholar
Leitch-Devlin, M.A. & Williams, D.A. 1985, MNRAS, 213, 295 Google Scholar
Masuda, K. & Takahashi, J. 1997, Adv. Space Res., 19, 1019 Google Scholar
Masuda, K., Takahashi, J., & Mukai, T. 1998, A&A, 330, 773 Google Scholar
Parneix, P. & Bréchignac, Ph. 1998, A&A, 334, 363 Google Scholar
Pirronello, V., Biham, O., Liu, C., Shen, L., & Vidali, G. 1997, ApJ, 483, L131 Google Scholar
Pirronello, V., Liu, C., Roser, J. E., & Vidali, G. 1999, A&A, 344, 681 Google Scholar
Takahashi, J., Masuda, K., & Nagaoka, M. 1999a, MNRAS, 306, 22 Google Scholar
Takahashi, J., Masuda, K., & Nagaoka, M. 1999b, ApJ, 520, 724 Google Scholar
Takahashi, J., Nagaoka, M., & Masuda, K. 1998, Int. J. Quantum Chem., 70, 379 Google Scholar
Takahashi, J. & Williams, D. A. 2000, MNRAS, in press Google Scholar
Williams, D.A. 1993, in Dust and Chemistry in Astronomy, eds. Millar, T.J. & Williams, D.A. (Institute of Physics Publishing: Philadelphia), 143 Google Scholar
Zhang, Q., Sabelli, N., & Buch, V. 1991, J. Chem. Phys., 95, 1080 Google Scholar