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Interpretation of low j 12CO and 13CO observations of Orion A by means of an onion shell radiative transfer model

Published online by Cambridge University Press:  03 August 2017

Klaus M. Gierens
Klaus M. Gierens*
Affiliation:
I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, D-5000 Köln, Fed. Rep. of Germany

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12CO and 13CO J = 1 → 0 and J = 2 → 1 observations of a 1 deg × 2 deg region centered on the BN/KL nebula in Orion A showed almost everywhere surprising intensity ratios. According to the standard interpretation of CO lines the 13CO TA (2 → 1)/TA (1 → 0) ratio meant optically thick and thermalized 13CO emission whereas at the same positions the 12CO/13CO intensity ratios indicated optically thin 13CO (Castets et al. 1989). Castets et al. (1990) suggested that temperature gradients in the observed clumps caused by external UV heating could be responsible for these results.

Type
Poster Sessions
Information
Symposium - International Astronomical Union , Volume 147: Fragmentation of Molecular Clouds and Star Formation , 1991 , pp. 413 - 414
Copyright
Copyright © Kluwer 1991 

References

Bally, J., Langer, W.D., Stark, A.A. and Wilson, R.W.: 1987, Astrophys. J. Letters 312, L45 Google Scholar
Castets, A., Duvert, G., Bally, J., Wilson, R.W. and Langer, W.D.: 1989, in The Physics and Chemistry of Interstellar Molecular Clouds, (Winnewisser, G. and Armstrong, J.T., Eds.), Springer, Heidelberg Google Scholar
Castets, A., Duvert, G., Dutrey, A., Bally, J., Langer, W.D. and Wilson, R.W.: 1990, Astron. Astrophys. 234, 469 Google Scholar
Cernicharo, J., Bachiller, R. and Duvert, G.: 1985, Astron. Astrophys. 149, 273 Google Scholar
Dickman, R.L. and Clemens, D.P.: 1983, Astrophys. J. 271, 143 Google Scholar
Gierens, K.M.: 1990, thesis, Universität zu Köln Google Scholar
Tielens, A.G.G.M. and Hollenbach, D.: 1985, Astrophys. J. 291, 722 Google Scholar