New members of the Scorpius-Centaurus complex and ages of its sub-regions

Abstract

We have spectroscopically identified ∼100 G-, K-, and M-type members of the Scorpius-Centaurus complex. To deduce the age of these young stars we compare their Liλ6708 absorption line strengths against those of stars in the TW Hydrae association and β Pictoris moving group. These line strengths indicate that Sco-Cen stars are younger than β Pic stars whose ages of ∼12Myr have previously been derived from a kinematic traceback analysis. Our derived age, ∼10Myr, for stars in the Lower Centaurus Crux and Upper Centaurus Lupus subgroups of ScoCen is younger than previously published ages based on the moving cluster method and upper main-sequence fitting. The discrepant ages are likely due to an incorrect (or lack of) cross-calibration between model-dependent and model-independent age-dating methods. © 2012. The American Astronomical Society. All rights reserved.