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A New Value for the Rotation Speed of the Spiral Structure

Published online by Cambridge University Press:  12 April 2016

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

Extract

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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
Information
International Astronomical Union Colloquium , Volume 45: Chemical and Dynamical Evolution of our Galaxy , September 1977 , pp. 293 - 296
Copyright
Copyright © Geneva Observatory 1977

References

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