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Giant molecular clouds in the galaxy: distribution, mass, size and age

Solomon, P. M. and Sanders, D. B. and Scoville, N. Z. (1979) Giant molecular clouds in the galaxy: distribution, mass, size and age. In: The Large-Scale Characteristics of the Galaxy. IAU Symposium Proceedings Series. No.84. D. Reidel , Dordrecht, pp. 35-52. ISBN 9789027710291.

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Millimeter wave observations of emission from the CO molecule have become, over the past eight years, the dominant method for determining the physical properties of dense interstellar clouds, composed primarily of molecular hydrogen and for exploring the structure and kinematics of the galactic disk. In this paper we briefly review the CO survey results in the literature (Section 2) and then present new results (Section 3-7) of an extensive ^(13)CO and ^(12)CO survey of the galactic distribution, size, mass and age of molecular clouds. The interpretation of this survey leads to a new picture of the interstellar medium dominated by very massive stable long-lived clouds which we refer to as Giant Molecular Clouds. We find that Giant Molecular Clouds (GMC's) with M = 10^5–3 × 10^6 M⊙ are a major constituent of the galactic disk, the dominant component of the interstellar medium in the galaxy interior to the sun and the most massive objects in the galaxy. We find that the interstellar medium and star formation are dominated by massive gravitationally bound clouds in which stars and associations are forming but at a very low rate in comparison to the free fall time. The galactic distribution of the molecules as traced by CO emission is interpreted as the distribution of GMC's. As the most massive objects in the galaxy they are also basic to the dynamics of the disk.

Item Type:Book Section
Related URLs:
URLURL TypeDescription
Sanders, D. B.0000-0002-1233-9998
Scoville, N. Z.0000-0002-0438-3323
Additional Information:© 1979 by the IAU. This work has been supported in part by NSF Grant AST 77-23419 at the State University of New York at Stony Brook.
Funding AgencyGrant Number
NSFAST 77-23419
Series Name:IAU Symposium Proceedings Series
Issue or Number:84
Record Number:CaltechAUTHORS:20181119-111842416
Persistent URL:
Official Citation:Solomon, P., Sanders, D., & Scoville, N. (1979). Giant molecular clouds in the galaxy: Distribution, mass, size and age. Symposium - International Astronomical Union, 84, 35-52. doi:10.1017/S0074180900014169
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:91021
Deposited By: Tony Diaz
Deposited On:19 Nov 2018 19:25
Last Modified:16 Nov 2021 03:37

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