Using the reduced proper motions of Tycho-2 stars with <Emphasis Type="Italic">B-V</Emphasis> from 0.75 to 1.25: Monte Carlo simulations |
| |
| Authors: | G A Gontcharov |
| |
| Institution: | 1.Pulkovo Astronomical Observatory,Russian Academy of Sciences,St. Petersburg,Russia |
| |
| Abstract: | The stellar composition of the Tycho-2 Catalogue in the range B-V = 0·
m
75–1·
m
25 has been reproduced through Monte Carlo simulations. For young and old stars of the red giant clump (RGC), the red giant
branch, subgiants, red dwarfs, and thick-disk giants, we have specified the distributions in coordinates, velocities, B-V, and M
V
as a function of B-V and calculated their reduced proper motions, photometric distances from the (B-V)-M
V
calibration, and photoastrometric distances from the reduced proper motion-M
V
calibration. Our simulations have shown the following: (1) a sample of thin-disk giants within 500 pc with an admixture of
less than 10% of other stars can be produced; (2) a sample of dwarfs within 100 pc almost without any admixture of other stars
can be produced; (3) the Local Spiral Arm affects the RGC composition of any magnitude-limited catalog in favor of giants
younger than 2 Gyr; (4) the samples produced using reduced proper motions can be used for kinematic studies, provided that
the biases of the quantities being determined are simulated and taken into account; (5) the photometric distances correlate
with the photoastrometric ones because of the correlation between the proper motion and magnitude; (6) the photometric distances
are closer to the true ones for the red giant branch and red dwarfs as the categories of stars with a clear (B-V)-M
V
relation, while the photoastrometric distances are closer to the true ones for the RGC, subgiants, and thick-disk giants;
(7) the calculated distances differ systematically from the true ones, but they can be used to analyze the three-dimensional
distribution of stars. Our simulations confirm the validity of our previous selection of RGC stars from Tycho-2. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
