Back to Search Start Over

The formation of interstellar molecular lines in a turbulent velocity field with finite correlation length

The formation of interstellar molecular lines in a turbulent velocity field with finite correlation length

Authors :
C. Hengel
Markus Röllig
M. Hegmann
W. H. Kegel
Source :
Astronomy & Astrophysics. 445:591-600
Publication Year :
2005
Publisher :
EDP Sciences, 2005.

Abstract

We present observational line data for five Bok Globules. Observations were made in the J = 2 → 1 and J = 3 → 2 rotational transitions of CO, 13 CO and C 18 O at the Heinrich-Hertz-Telescope in Arizona. Using the stochastic radiative transfer model (SRTM) based on the generalized radiative transfer equation as described in the previous papers of this series, we were able to fit the observed CO lines for four of the five Bok globules. The derived parameters such as the hydrogen density, the cloud mass and temperature in part differ significantly from values obtained from a standard LVG analysis or a microlurbulent approach. The best fits are obtained for models characterized by a ratio of the mean free path of photons to the correlation length of the turbulent velocity field of the order of unity. This is what characterizes the mesolurhulent regime that cannot be dressed by standard evaluation methods like LVG or microturbulent approximations.

Details

ISSN :
14320746 and 00046361
Volume :
445
Database :
OpenAIRE
Journal :
Astronomy & Astrophysics
Accession number :
edsair.doi...........03ef8a0d9ad4c65c3b7963ae0da6e999
Full Text :
https://doi.org/10.1051/0004-6361:20041881