Publication Abstracts

De Vries et al. 1987

De Vries, H.W., A. Heithausen, and P. Thaddeus, 1987: Molecular and atomic clouds associated with infrared cirrus in Ursa Major. Astrophys. J., 319, 723-729, doi:10.1086/165492.

Observations of CO and H I revealed that in Ursa Major the high-latitude far-infrared "cirrus" emission discovered by the Infrared Astronomical Satellite comes from molecular and atomic clouds. These clouds differ sufficiently from the large clouds in the Galactic plane so that the ratio of H2 column density to velocity-integrated CO radiation temperature, N(H2)/W(CO), derived from Galactic plane surveys, may not apply to them. On the assumption of a constant gas-to-dust ratio, it is argued that the cirrus emission in Ursa Major is a good mass tracer, since both the atomic and the molecular gas are probably optically thin at visual wavelengths, and the grains are heated not by local sources but by the background field of Galactic starlight. The N(H2)/W(CO) ratio thus derived for those diffuse clouds, (0.5±0.3)×1020 K-1km-1s/cm2, is significantly lower than the ratio applicable to Galactic plane surveys.

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BibTeX Citation

@article{de04300u,
  author={de Vries, H. W. and Heithausen, A. and Thaddeus, P.},
  title={Molecular and atomic clouds associated with infrared cirrus in Ursa Major},
  year={1987},
  journal={Astrophys. J.},
  volume={319},
  pages={723--729},
  doi={10.1086/165492},
}

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RIS Citation

TY  - JOUR
ID  - de04300u
AU  - de Vries, H. W.
AU  - Heithausen, A.
AU  - Thaddeus, P.
PY  - 1987
TI  - Molecular and atomic clouds associated with infrared cirrus in Ursa Major
JA  - Astrophys. J.
VL  - 319
SP  - 723
EP  - 729
DO  - 10.1086/165492
ER  -

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