OBSERVATIONS OF INTERSTELLAR GAS TOWARDS OMEGA-CENTAURI AND THE CARINA-SAGITTARIUS SPIRAL ARM

Interstellar Na D and K i line spectra are reported for three stars wh ich lie within 5-degrees of the omega Cen cluster. These new data have enabled us to complete the identification of the absorption component s which are observed in the gas foreground to this cluster. In particu lar, we discuss a component at velocity v(lsr) almost-equal-to -15 km s-1 which is produced by gas beyond almost-equal-to 1 kpc and at a dis tance greater than or similar 175 pc above the Galactic plane. We sugg est that this feature originates in the gas of the Carina spiral arm. Weaker components having negative peculiar velocities appear to lie be yond the bulk of the -15 km s-1 gas. A comparison of these new observa tions with similar studies made towards M4 and M22 provides a further indication of the complex structure of the gas over part of the Carina -Sagittarius arm region.