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Molecular hydrogen emission in NGC 7027

Beckwith, S. and Neugebauer, G. and Becklin, E. E. and Matthews, K. and Persson, S. E. (1980) Molecular hydrogen emission in NGC 7027. Astronomical Journal, 85 (7). pp. 886-890. ISSN 0004-6256. doi:10.1086/112753.

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The spatial distribution of the emission in the v = 1-0 S(1) line of H2 in the planetary nebula NGC 7027 is presented. The excited H2 molecules do not fill the same volume as the ionized gas and most likely reside near the outer edge of the nebula. The spatial resolution of the data, 5 arcsec, is insufficient to define the location of the molecules precisely. An upper limit to the strength of the v = 2-1 S(1) line is given; it is low enough to preclude simple ultraviolet fluorescence as the source of excitation. A simple shock model can fit the line ratio data, however, and there is enough energy in the expanding nebula to sustain such a shock. A rough estimate of 1 M_⊙ to 4 M_⊙ for the mass in the molecular cloud surrounding NGC 7027 is derived.

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Additional Information:© 1980 American Astronomical Society. Received 25 January 1980; revised 3 April 1980. We thank our night assistant Juan Carrasco for help with the observations, and we are grateful to Dr. T. N. Gautier, III, the referee, for his helpful suggestions and for pointing out an error in the original text. This work was supported in part by NSF Grant AST 77-20516 and NASA Grant NGL 05-002-207.
Funding AgencyGrant Number
NSFAST 77-20516
NASANGL 05-002-207
Issue or Number:7
Record Number:CaltechAUTHORS:20170322-162615695
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:75332
Deposited By: George Porter
Deposited On:23 Mar 2017 20:26
Last Modified:15 Nov 2021 16:32

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