The violent interstellar medium associated with the Carina Nebula. I.The line of sight toward HD 93205.

Abstract

Four high velocity and two low velocity components have been identified by the analysis of interstellar absorption lines in high resolution spectra of HD 93205. The chemical composition and physical conditions of the different regions are discussed in light of UV, optical and radio observations, and the two main high velocity components are found to show different relative abundance patterns. Among the two low velocity components, one has been identified with the normal interstellar material in the disk of the Galaxy between the sun and the Carina nebula. Column densities of interstellar C IV and Si IV have been measured in this component, free from contamination by circumstellar material. The other low velocity component has been identified with the approaching part of the expanding ionized nebula around the Carina OB associations, and consists of a dense H II region in which the two O I fine structure lines originate.