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arXiv · 0809.3381

Periodic Pattern in the Residual-Velocity Field of OB Associations

A. M. Mel'nik·A. K. Dambis·A. S. Rastorguev
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Abstract

An analysis of the residual-velocity field of OB associations within 3 kpc of the Sun has revealed periodic variations in the radial residual velocities along the Galactic radius vector with a typical scale length of lambda=2.0(+/-0.2) kpc and a mean amplitude of fR=7(+/-1) km/s. The fact that the radial residual velocities of almost all OB-associations in rich stellar-gas complexes are directed toward the Galactic center suggests that the solar neighborhood under consideration is within the corotation radius. The azimuthal-velocity field exhibits a distinct periodic pattern in the region 0<l<180 degrees, where the mean azimuthal-velocity amplitude is ft=6(+/-2) km/s. There is no periodic pattern of the azimuthal-velocity field in the region 180<l<360 degrees. The locations of the Cygnus arm, as well as the Perseus arm, inferred from an analysis of the radial- and azimuthal-velocity fields coincide. The periodic patterns of the residual-velocity fields of Cepheids and OB associations share many common features.

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A. M. Mel'nik, A. K. Dambis, A. S. Rastorguev. 2008-09-19. Periodic Pattern in the Residual-Velocity Field of OB Associations. https://doi.org/10.1134/1.1388920

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