Kinematics of the Scorpius-Centaurus OB association
Abstract
A fine structure related to the kinematic peculiarities of three components of the Scorpius-Centaurus association (LCC, UCL, and US) has been revealed in the UV-velocity distribution of Gould Belt stars. We have been able to identify the most likely members of these groups by applying the method of analyzing the two-dimensional probability density function of stellar UV velocities that we developed. A kinematic analysis of the identified structural components has shown that, in general, the center-of-mass motion of the LCC, UCL, and US groups follows the motion characteristic of the Gould Belt, notably its expansion. The entire Scorpius-Centaurus complex is shown to possess a proper expansion with an angular velocity parameter of 46 ± 8 km s−1 kpc−1 for the kinematic center with l0 = −40° and R0 = 110 pc found. Based on this velocity, we have estimated the characteristic expansion time of the complex to be 21 ± 4 Myr. The proper rotation velocity of the Scorpius-Centaurus complex is lower in magnitude, is determined less reliably, and depends markedly on the data quality.
- Publication:
-
Astronomy Letters
- Pub Date:
- September 2007
- DOI:
- arXiv:
- arXiv:0708.0943
- Bibcode:
- 2007AstL...33..571B
- Keywords:
-
- star clusters and associations;
- stellar dynamics;
- Scorpius-Centaurus association;
- Gould Belt;
- kinematics;
- open star clusters;
- Astrophysics
- E-Print:
- 21 pages, 7 figures