Para/ortho abundance ratio of molecular hydrogen in NGC 2023
Journal Article
·
· Astrophys. J.; (United States)
Recent infrared emission-line observations by Hasegawa et al. (1987) clearly indicate that the para/ortho abundance ratio of H2 in the reflection nebula NGC 2023 is quite different from 1:3. A simplified steady-state problem is solved to determine the vibrational-rotational level population. In addition to radiative processes, the H2 formation on grains and the gas-phase para/ortho conversion processes are taken into account. A good fit to the observed line intensity ratio can be obtained if the rotational Boltzmann distribution with temperature Tf = 60-70 K is assumed for H2 formed on grain surface. 28 references.
- Research Organization:
- Tokyo Univ., Japan
- OSTI ID:
- 6174108
- Journal Information:
- Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 318; ISSN ASJOA
- Country of Publication:
- United States
- Language:
- English
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