EDP Sciences
Free Access
Volume 460, Number 3, December IV 2006
Page(s) 695 - 708
Section Galactic structure, stellar clusters, and populations
DOI https://doi.org/10.1051/0004-6361:20065602

A&A 460, 695-708 (2006)
DOI: 10.1051/0004-6361:20065602

Search for associations containing young stars (SACY)

I. Sample and searching method
C. A. O. Torres1, G. R. Quast1, L. da Silva2, R. de la Reza2, C. H. F. Melo3, 4, and M. Sterzik3

1  Laboratório Nacional de Astrofísica/MCT, Rua Estados Unidos 154, 37504-364 Itajubá, Brazil
    e-mail: beto@lna.br
2  Observatório Nacional/MCT, 20921-400 Rio de Janeiro, Brazil
3  European Southern Observatory, Casilla 19001, Santiago 19, Chile
4  Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago, Chile

(Received 12 May 2006 / Accepted 12 August 2006)

We report results from a high-resolution optical spectroscopic survey aimed to search for nearby young associations and young stars among optical counterparts of ROSAT All-Sky Survey X-ray sources in the Southern Hemisphere. We selected 1953 late-type ( $B-V~\geq~0.6$), potentially young, optical counterparts out of a total of 9574 1RXS sources for follow-up observations. At least one high-resolution spectrum was obtained for each of 1511 targets. This paper is the first in a series presenting the results of the SACY survey. Here we describe our sample and our observations. We describe a convergence method in the (UVW) velocity space to find associations. As an example, we discuss the validity of this method in the framework of the $\beta$ Pic Association.

Key words: stars: pre-main sequence -- stars: formation -- stars: kinematics -- stars: rotation -- stars: abundances -- open clusters and associations: individual: $\beta$ Pictoris

© ESO 2006