Hostname: page-component-78c5997874-fbnjt Total loading time: 0 Render date: 2024-11-19T10:39:43.427Z Has data issue: false hasContentIssue false

A New Value for the Rotation Speed of the Spiral Structure

Published online by Cambridge University Press:  12 April 2016

J. Palouš*
Affiliation:
Astronomical Institute of the Czechoslovak Academy of Sciences, Prague, Czechoslovakia

Extract

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 basic model of our Galaxy, like the Schmidt (1965) model, obeys the density law ρ(R) for the Galaxy based on divers evidence, less or better known from observation. The interpretation of the interstellar hydrogen radio profiles yields the rotation curve and the run of the force component in the radial direction. The Oort constants A, B known from radial velocities and proper motions of nearby stars, the distance from the Sun to the galactic center Ro established from the distances of RR Lyrae stars, the local density and density gradients in the vicinity of the Sun, known from the star counts, are involved in this basic model of the Galaxy. The r.m.s. velocity component in the z direction yields the approximate mass distribution in this direction. The model surface density is computed by integrating the density along the z direction in the model. The local surface density in the Schmidt model is 114 solar masses per pc2; it depends rather strongly on the assumed density variation in the outer part of the Galaxy.

Type
Part IV: Kinematics and Dynamical Evolution of the Galaxy
Copyright
Copyright © Geneva Observatory 1977

References

Lin, C.C., Shu, F.H., Yuan, C. 1969, Astrophys. J. L55, 721 Google Scholar
PalouS, J., Ruprecht, J., Dluzhnevskaya, O.B., Piskunov, T. 1977, Astron. Astrophys., in pressGoogle Scholar
Schmidt, M. 1965, Rotation Parameters and Distribution of Mass in the Galaxy, in Galactic Structure, Eds. Blaauw, A. and Schmidt, M., University Chicago Press, Chicago, p. 513 Google Scholar
Toomre, A. 1964, Astrophys. J. 139, 1217 CrossRefGoogle Scholar
Wielen, R. 1974, The Kinematics and Ages of Stars in Gliese’s Catalogue, in Highlights of Astronomy, Ed. Contopoulos, G., p. 395 CrossRefGoogle Scholar
Yuan, C. 1969 a, Astrophys. J. 158, 871 CrossRefGoogle Scholar
Yuan, C. 1969 b, Astrophys. J. 158, 889 CrossRefGoogle Scholar