Astron. Astrophys. 329, 514-521 (1998)

Investigation of the kinematics of young disk populations

E.V. Glushkova, A.K. Dambis, A.M. Mel'nik and A.S. Rastorguev

Sternberg Astronomical Institute, Universitetskii pr. 13, Moscow, 119899 Russia

Received 28 January 1997 / Accepted 28 April 1997

Abstract

We used both radial-velocity and proper-motion data to perform a rotation-curve solution on a combined sample of about 700 Population-I objects including young open clusters (lg A 8.1), classical Cepheids, and red supergiants. The distances of all objects are derived on a homogenized scale based on Kholopov's (1980) ZAMS, , PL relation for classical Cepheids by Berdnikov & Efremov (1985), and the absolute-magnitude calibration for red supergiants involving photometric data in Wing's eight-color narrow-band near-infrared system. We inferred = 7.3 0.3 kpc for the distance of the Sun to the Galactic center and found the following parameters of the solar apex and Galactic rotation curve: = 8.8 0.9 km s^-1, = 13.5 0.9 km s^-1, = 11.7 1.5 km s^-1, = 27.3 2.0 km s^-1 kpc^-1, A = 19.5 0.5 km s^-1 kpc^-1, and = 1.13 0.12 km s^-1 kpc^-3. These values are in good agreement with the results of our analysis of the radial-velocity and proper-motion fields of classical Cepheids (Dambis et al. 1995).

Key words: Galaxy: kinematics and dynamics open clusters and associations Cepheids supergiants Galaxy: structure Galaxy: fundamental parameters

© European Southern Observatory (ESO) 1998

Online publication: December 8, 1997
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