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Kinematics of Nearby Gas and Stars

Published online by Cambridge University Press:  12 April 2016

Thomas Goulet
Affiliation:
Department of Physics, University of British Columbia
William L.H. Shuter
Affiliation:
Department of Physics, University of British Columbia

Abstract

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The kinematic properties of gas and stars in the Solar neighborhood are described in terms of the line-of-sight component of a three-dimensional first order Taylor series expansion of the local velocity field. The types of object analysed are (1) 21 cm absorbing clouds (2) intercloud medium (3) main sequence B stars closer than 200 pc (4) B stars of luminosity class ranging from I to IV (5) main sequence A stars (6) K-giant stars. The least squares fitting procedure used to derive the 10 coefficients describing each of the six velocity fields was essentially the same, so that a valid comparison could be made. Marked departures from circular motion are found in most cases, but the only systematic trend is a correlation between ∂u/∂x (u being the velocity component along the x-axis directed towards the Galactic center) and stellar spectral type, where the gas behaves like a medium ‘younger’ than the early type stars. Our analysis of the gas indicated that the standard plane-parallel model provided a good description for the intercloud medium, but was inadequate for the absorbing clouds. A velocity ellipsoid description of the residuals is presented for each type of object. The influence of the Gould belt on local kinematics is discussed.

Type
Theoretical Models
Copyright
Copyright © NASA 1984

References

Crovisier, J., Kazes, J., and Aubry, D. 1978, Astronomy and Astrophysics Suppl., 32, 205.Google Scholar
Goulet, T., 1984, M.Sc. Thesis, University of British Columbia, (in preparation). Google Scholar
Helfer, H.L. 1961, Astronomical Journal, 66, 160. Google Scholar
Henderson, A.P. 1973, Astronomical Journal, 78, 381. Google Scholar
Hirshfeld, A., and Sinnott, R. 1982, Sky Catalogue 2000.0, Volume 1, Cambridge University Press and Sky Publishing Corporation. Google Scholar
McGee, R.X., and Murray, J.D. 1961,Australian Journal of Physics, 14, 260. Google Scholar
Mihalas, D., and Binney, J. 1981, Galactic Astronomy, Structure and Kinematics, Freeman, W.H., San Francisco.Google Scholar
Olano, C.A. 1982, Astronomy and Astrophysics, 112, 195. Google Scholar
Takakubo, K. 1967, Bull. Astr. Inst. Neth., 19, 125.Google Scholar
Weaver, H. 1974, in Highlights of Astronomy, Vol. 3, Contopoulos, G. (ed.), D. Reidel Publishing Co., Dordrecht.Google Scholar