Abstract
The photodissociation rate of H2 molecules by UV photons from PN central stars is generally several orders of magnitude larger than the rate produced by the average interstellar field (Sternberg 1988, Escalante el al. 1991). Thus, in neutral envelopes of PN’s, H2 molecules are destroyed quickly, and a photodissociation region forms around ionization bounded nebulae. Observations of H2 in PN’s reveal that not all the hydrogen is photodissociated, and it has been suggested that this is due to the existence of dense disks around the ionized region (Zuckerman and Gatley 1988).
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References
Escalante, V., Sternberg, A., and Dalgarno, A., 1991, Ap. J. 375, 630.
Gómez, Y., Moran, J.M., Rodríguez, L.F., and Garay, G., 1989, Ap. J. 354, 862.
Sternberg, A., 1988, Ap. J. 332, 400.
Taylor, A.R., Gussie, G.T., and Pottasch, S.R., 1990, Ap. J. 351, 515.
Zuckerman, B., and Gatley, I., 1988, Ap. J. 324, 501.
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© 1993 Springer Science+Business Media Dordrecht
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Escalante, V., Góngora-T, A. (1993). Photodissociation Regions in Planetary Nebulae. In: Weinberger, R., Acker, A. (eds) Planetary Nebulae. International Astronomical Union / Union Astronomique Internationale, vol 155. Springer, Dordrecht. https://doi.org/10.1007/978-94-011-2088-3_92
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DOI: https://doi.org/10.1007/978-94-011-2088-3_92
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