High resolution observations of interstellar Na I and Ca II towards the Scorpius OB1 association

Observations of Na I and Ca II in absorption toward 22 stars in the Sco OB1 region, obtained at resolution R = 100,000 with a coude echelle spectrograph and 3.3-m camera on the 1.9-m telescope at Mt. Stromlo Observatory during 1986, are reported. The data are presented in extensive tables and graphs and analyzed in detail. Features discussed include (1) strong absorption at heliocentric velocities between 0 and -20 km/sec, (2) sharp discrete components with blueshifted velocities of up to -50 km/sec, and (3) some absorption at positive heliocentric velocities up to +20 km/sec. The (Na I)/(Ca II) ratios are found to be 4-200 for component (1), near 1 for component (2), and 0.4 or less for component (3