Spectrophotometric Results from the Copernicus Satellite. II. Composition of Interstellar Clouds

Abstract

Interstellar absorption lines of H I, C I, C ii, N I, N H, 0 1, Mg I, Mg H, Si H, Si iu, Si Iv, P ii, S I, SH, Sm, S Iv, Cl H, Ar I, Mn ii, and Fe ii have been identified in scans of one or more of the reddened stars Per, a Cam, N Ori, Oph, and Ara. A curve-of-growth analysis of abundances shows that the ratios of Mg, P, Cl, and Mn to hydrogen are less than in the Sun by factors of about 4 to 10. Several of the other elements also are depleted in some of the stars. Excited levels in the ground terms of C I, C Ir, N H, and Si H also are present. Subject headings: abundances - interstellar matter - spectra, ultraviolet - spectrophotometry