The vertical velocity dispersion profile of the Galactic thick disk
Astrophysics
2007-12-21 v1
Abstract
We present the results of radial velocity measurements of 770 thick disk red giants toward the South Galactic Pole, vertically distributed from 0.5 kpc to 5 kpc with respect to the Galactic plane. We find a small gradient in the vertical velocity dispersion (sigma_W) of 3.8+/-0.8 km/s kpc. Even more noteworthy, our values of are small compared to literature values: in the middle of the vertical height range we find sigma_W(z=2kpc)=30 km/s. We found no possible explanation for this small value of sigma_W in terms of sample contamination by thin disk stars, nor by wrong assumptions regarding the metallicity distribution and the derived distances.
Keywords
Cite
@article{arxiv.0712.3528,
title = {The vertical velocity dispersion profile of the Galactic thick disk},
author = {C. Moni Bidin and T. M. Girard and G. Carraro and R. A. Mendez and W. F. van Altena and V. I. Korchagin and D. I. Casetti-Dinescu},
journal= {arXiv preprint arXiv:0712.3528},
year = {2007}
}
Comments
2 pages, 1 figure, proceeding of the XII IAU Latin American Regional Meeting