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13CO AND C18O observations of the SGR B2 molecular cloud molecular abundances and column densities

  • Molecular Cloud Properties
  • Conference paper
  • First Online:
Molecular Clouds in the Milky Way and External Galaxies

Part of the book series: Lecture Notes in Physics ((LNP,volume 315))

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Abstract

We have observed the J=1-)»0 transition of 13CO and C18O in the Sagittarius B2 molecular cloud. The observations yield the average 13CO to C18O abundance ratio of 9.5 ± 2.2 . The peak H2 column density corresponds to the position of the SgrB2(M) continuum source (α = 17h44m10.5s, δ = −28°22′05″. Comparison of molecular column densities with H2 column densities derived from 1300 μ continuum data leads to the conclusion that the fractional abundances of CO isotopes in the region are lower than the typical values characteristic of the disk. With a 13CO to H2 fractional abundance of 10−6, the total mass of the region mapped is 4 x 106 M⊙.

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References

  • Dickman, R.L. 1978, Ap. J. Suppl., 37, 407.

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Authors and Affiliations

  1. Five College Radio Astronomy Observatory, University of Massachusetts, 01003, Amherst, MA

    Dariusz C. Lis & Paul F. Goldsmith

Authors
  1. Dariusz C. Lis
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  2. Paul F. Goldsmith
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Editor information

Robert L. Dickman Ronald L. Snell Judith S. Young

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© 1988 Springer-Verlag

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Lis, D.C., Goldsmith, P.F. (1988). 13CO AND C18O observations of the SGR B2 molecular cloud molecular abundances and column densities. In: Dickman, R.L., Snell, R.L., Young, J.S. (eds) Molecular Clouds in the Milky Way and External Galaxies. Lecture Notes in Physics, vol 315. Springer, Berlin, Heidelberg. https://doi.org/10.1007/3-540-50438-9_266

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  • DOI: https://doi.org/10.1007/3-540-50438-9_266

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  • Publisher Name: Springer, Berlin, Heidelberg

  • Print ISBN: 978-3-540-50438-2

  • Online ISBN: 978-3-540-46003-9

  • eBook Packages: Springer Book Archive

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