We present results of a spectroscopic survey of X-ray and proper-motion-selected samples of late-type stars in the Lower Centaurus-Crux (LCC) and Upper Centaurus-Lupus (UCL) subgroups of the nearest OB association: Scorpius-Centaurus. The primary goals of the survey are to determine the star formation history of the OB subgroups and to assess the frequency of accreting stars in a sample dominated by "post-T Tauri" pre-main-sequence (PMS) stars. We investigate two samples: (1) proper-motion candidates from the ACT Catalog () and Tycho Reference Catalog (TRC, ) with X-ray counterparts in the ROSAT All-Sky Survey (RASS) Bright Source Catalog and (2) G- and K-type stars in the Hipparcos catalog found to be candidate members by de Zeeuw et al. (1999, Cat. ). We obtained optical spectra of 130 candidates with the Siding Spring 2.3m dual-beam spectrograph.

Cone search capability for table J/AJ/124/1670/table1 (Properties of de Zeeuw et al. (1999, Cat. ) Sco-Cen G-K candidate members)

Cone search capability for table J/AJ/124/1670/table2 (Properties of RASS-ACT/TRC candidates)

Cone search capability for table J/AJ/124/1670/table4 (LCC and UCL pre-main-sequence members from de Zeeuw et al. (1999, ) list)

Cone search capability for table J/AJ/124/1670/table5 (Pre-main sequence LCC & UCL RASS-ACT/TRC members)

Cone search capability for table J/AJ/124/1670/table6 (RASS-ACT/TRC and HIPPARCOS stars rejected as Sco-Cen members)