Measurement and interpretation of deuterium-line emission in the orion nebula
Por:
O'Dell C.R., Ferland G.J., Henney W.J.
Publicada:
1 ene 2001
Resumen:
We present new observations of the deuterium and hydrogen Balmer lines in the Orion Nebula. There is a real variation in the deuterium-to-hydrogen line ratios across the nebula, being greatest in the emission from the largest proplyd (Orion 244-440). We also present the results of a detailed model for the emission of these lines, the hydrogen lines being the result of photoionization and recombination while the deuterium lines are produced by fluorescent excitation of the upper energy states by the far-UV radiation from ?1 Ori C. Comparison of the observations and predictions of the line intensities shows good agreement, both in the strength of the reference lines at H? and also in the differences of the Balmer decrement for the two atoms. The fact that both the deuterium and hydrogen emissions arise from mechanisms that count the near-ultraviolet (deuterium) and photoionizing ultraviolet (hydrogen) photons from the dominant star means that there is little prospect of similar observations being useful for determination of D/H abundances in H II regions.
Filiaciones:
O'Dell C.R.:
Department of Physics and Astronomy, Vanderbilt University, Box 1807-B, Nashville, TN 37235, United States
Ferland G.J.:
Department of Physics and Astronomy, 177 CP Building, University of Kentucky, Lexington, KY 40506-0055, United States
Henney W.J.:
Instituto de Astronomía, UNAM Campus Morelia, Apartado Postal 3-72 (Xangari), 58089 Morelia, Michoacán, Mexico
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