Astron. Astrophys. Suppl. Ser. 144, 123-140
J.G.A. Wouterloot 1,2 - A. Heithausen 1 - W. Schreiber 2 - G. Winnewisser 2
Send offprint request: J.G.A. Wouterloot,
1 - Radioastronomisches Institut, Universität Bonn, Auf dem Hügel 71, D-53121 Bonn, Germany
2 - I. Physikalisches Institut, Universität zu Köln, Zülpicher Strasse 77, D-50937 Köln, Germany
Received October 5, 1999; accepted February 2, 2000
Our data show that MBM 32 consists of a main cloud component at kms-1 (mass about 16.9 ), and a smaller component at kms-1 (4.1 ), in addition to some emission in between those two velocities (<0.5 ).
We study the gas distribution and the CO line ratios within MBM 32, the latter also along a cut through both cloud components. We find that the ratios of different rotational transitions are constant within each cloud part. Only the ratio 12CO( 1-0)/13CO(1-0) is lower in the cloud center. This suggests equal excitation conditions through MBM32 and line temperatures determined through clump filling factors.
All CO components show associated H I emission, but small velocity differences of typically 1 kms-1 exist between the H I and CO gas. The mass of associated H I gas is similar to the molecular mass for all components.
There is a good correlation between FIR, CO, and H I emission. The dust mass is about 0.073 , and the ratio of gas and dust mass (280) is lower than found from similar (IRAS) data for denser clouds, suggesting that the amount of dust colder than 20 K is relatively small.
We subdivide the CO data cubes in Gaussian shaped clumps; 40-50% of the CO emission can be assigned to the larger clumps. The remaining emission comes from either more extended clumps or from overlapping unresolved clumps.
Key words: ISM: clouds -- ISM: individual objects: MBM 32 -- ISM: molecules --
radio lines: ISM
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