Hostname: page-component-cd9895bd7-gbm5v Total loading time: 0 Render date: 2024-12-24T15:38:15.380Z Has data issue: false hasContentIssue false
  • English
  • Français

A Complete CO Survey of M31

Published online by Cambridge University Press:  03 August 2017

T. M. Dame ,
E. Koper ,
F. Israel  and
P. Thaddeus
T. M. Dame
Affiliation:
Harvard-Smithsonian Center for Astrophysics 60 Garden Street Cambridge, Mass. 01238
E. Koper
Affiliation:
Leiden Observatory P.O. Box 9513 2300 RA Leiden The Netherlands
F. Israel
Affiliation:
Leiden Observatory P.O. Box 9513 2300 RA Leiden The Netherlands
P. Thaddeus
Affiliation:
Harvard-Smithsonian Center for Astrophysics 60 Garden Street Cambridge, Mass. 01238

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The 1.2 m telescope at the Center for Astrophysics is being used to carry out the first complete CO survey of M31. To date, the entire galaxy out to a radius of at least 15 kpc —- well beyond the optical disk and H I ring — has been observed every half-beamwidth (4.5'), with ∼1 hr of integration per point yielding an rms of 20 mK in 1.3 km s—1 channels. Like H I and other Population I tracers, molecular clouds in M31 are mainly concentrated in a broad ring with a radius of ∼10 kpc, but beyond the peak of the ring molecular gas falls off more sharply than atomic gas. On the assumption of a standard Galactic value for the conversion of CO emission to H2 mass, the average molecular surface density at the peak of the ring is ∼1 M⊙ pc-2 and the total molecular mass of M31 is ∼3 × 108 M⊙. The survey will be essentially repeated during the coming year to improve the signal-to-noise.

Type
I- Local Group Galaxies
Information
Symposium - International Astronomical Union , Volume 146: Dynamics of Galaxies and their Molecular Cloud Distributions , 1991 , pp. 23 - 26
Copyright
Copyright © Kluwer 1991 

References

Cram, T. R., Roberts, M. S., and Whitehurst, R. N. 1980, Astr. Ap. Suppl., 40, 215.Google Scholar
Lucy, L. B. 1974, A. J., 79, 745.CrossRefGoogle Scholar
Ryden, B. S., and Stark, A. A. 1986, Ap. J., 305, 823.CrossRefGoogle Scholar
Strong, A. W., Bloemen, J. B. G. M., Dame, T. M., Grenier, I. A., Hermsen, W., Lebrun, F., Nyman, L.-Å., Pollock, A. M. T., and Thaddeus, P. 1988, Astr. Ap., 207, 1.Google Scholar
Unwin, S. C. 1980, M.N.R.A.S., 192, 243.CrossRefGoogle Scholar
Walterbos, R. A. M., and Schwering, P. B. W. 1987, Astr. Ap., 180, 27.Google Scholar