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Dynamical Constraints on Massive Star Formation

Published online by Cambridge University Press:  03 August 2017

William H. Waller
Affiliation:
University of Washington Dept. of Astronomy, FM-20 Seattle, Washington 98195 U.S.A.
Paul W. Hodge
Affiliation:
University of Washington Dept. of Astronomy, FM-20 Seattle, Washington 98195 U.S.A.

Abstract

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Extragalactic HII regions and their ionizing star clusters are the most prominent signposts of recent starbirth activity in galaxies. In this paper, we present optical measurements of nearby extragalactic HII regions with the aim of investigating possible relationships between the newborn ionizing clusters and their dynamical environment. Evidence for variations in the measured HII region properties (size, Hα luminosity, and Hα equivalent width) are presented as a function of galaxy type and of position within individual galaxies. These variations, in turn, are compared with the corresponding kinematic and dynamical variations. The apparent sensitivity of the ionizing activity to the dynamical environment suggests that the total masses and upper stellar mass limits of the ionizing clusters are somehow constrained by the ambient tidal stresses and shear flows within the galaxies. We speculate that regions of high tidal stress and kinematic shearing tend to suppress the formation and maintenance of giant molecular clouds, thereby hindering the creation of giant clusters and massive stars therein.

Type
VI- Other Gaseous Components
Copyright
Copyright © Kluwer 1991 

References

Blitz, L. and Glassgold, A. E. 1982, Ap. J., 252, 481.Google Scholar
Brosche, P. 1971, Astr. Ap., 13, 293.Google Scholar
Elmegreen, B. G. 1987a, Ap. J., 312, 626.Google Scholar
Elmegreen, B. G. 1987b, in Physical Processes in Interstellar Clouds, eds. Morfill, G. E. and Scholer, M. (Dordrecht: Reidel), p. 1.Google Scholar
Elmegreen, B. G. 1987c, in Comets to Cosmology, ed. Lawrence, A. (Berlin: Springer-Verlag), p. 186.Google Scholar
Hodge, P. W. and Kennicutt, R. C. 1983, A. J., 88, 296.CrossRefGoogle Scholar
Kennicutt, R. C. Jr. 1988, Ap. J., 334, 144.CrossRefGoogle Scholar
Kennicutt, R. C. Jr., Edgar, K. B., and Hodge, P. W. 1989, Ap. J., 337, 761.Google Scholar
Rubin, V. C., Ford, W. K. Jr., and Thonnard, N. 1978, Ap. J. (Letters), 225, L107.Google Scholar
Scoville, N. Z., Yun, M. J., Clemens, D. P., Sanders, D. B., and Waller, W. H. 1987, Ap. J. Suppl., 63, 821.Google Scholar
Smith, T. R. and Kennicutt, R. C. Jr. 1989, Pub. A. S. P., 101, 649.Google Scholar
Stark, A. A. and Blitz, L. 1978, Ap. J. (Letters), 225, L15.CrossRefGoogle Scholar
Waller, W. H., Clemens, D. P., Sanders, D. B., and Scoville, N. Z. 1987, Ap. J., 314, 397.Google Scholar
Waller, W. H. 1990, Recent Starbirth and Starburst Activity in Nearby Galaxies, Ph.D. Dissertation, University of Massachusetts.Google Scholar