Dense cores of dark clouds.: XII.: 13CO and C18O in Lupus, Corona Australis, Vela, and Scorpius

More than 110 dense condensations of the dark clouds in Lupus, Corona Australis, Norma, Vela, and Scorpius were observed in the (CO)-C-13 and (CO)-O-18 (J = 1-0) transitions. The condensations of dark clouds with high star formation activity like the Ophiuchus, Taurus, and Cepheus have average (CO)-O-18 and H-2 column densities of 1.8 x 10(15) and 1.1 x 10(22) cm(-2). If We take the average size of the condensations to be 0.2 pc, a condensation must have average H-2 volumetric densities greater than or equal to 2 x 10(4) cm(-3) in order to ea good candidate to form stars. The four Lupus filaments have similar radial velocities and velocity dispersions, suggesting that they originated from the same parental cloud. Among these filaments, Lupus 1 is unique in having recent star formation activity, despite the high number of T Tauri stars observed toward the others. Lupus 1 also shows a complex velocity gradient along its main axis. The distribution of radial velocities of the condensations observed toward Scorpius are in good agreement with the hypothesis that they are in a region with expansion velocity smaller than or equal to 18 km s(-1). The Corona Australis cloud has velocity gradients ranging from -0.5 km s(-1) pc(-1) at one extreme to 0.1 km s(-1) pc(-1) at the other.