Interstellar absorption lines in the spectrum of zeta Ophiuchi

Abstract

view Abstract Citations (639) References (104) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Interstellar absorption lines in the spectrum of Zeta Ophiuchi. Morton, D. C. Abstract Extensive high-resolution scans with the Copernicus UV spectrometer are combined with available ground-based data on interstellar lines to obtain temperatures, densities, and abundances in H I clouds and H II regions in the direction of zeta Oph. Column densities are obtained for 21 elements in various ionization stages, and upper limits are reported for 5 elements and 11 molecules. Analysis of radial velocities and growth curves indicates that H2, HD, and most neutral atoms are concentrated in one cloud with a heliocentric velocity of -14.4 km/s and that H II regions exist in addition to the Stroemgren sphere. The electron and proton densities are calculated for the -14.4 km/s cloud, and the temperatures required for the populations of the fine-structure levels in the C I ground state and the excited rotational levels of H2 are computed and indicate that the dense cloud must have some associated hotter regions. Relative to hydrogen, most of the elements in the H I clouds are found to be depleted by factors of 3 to 4000 as compared with solar system abundances, and several elements appear to be depleted in the H II regions as well. Publication: The Astrophysical Journal Pub Date: April 1975 DOI: 10.1086/153490 Bibcode: 1975ApJ...197...85M Keywords: Absorption Spectra; Astronomical Spectroscopy; Interstellar Extinction; Line Spectra; Ultraviolet Spectra; Abundance; Far Ultraviolet Radiation; Fine Structure; H Ii Regions; Hydrogen Atoms; Hydrogen Ions; Lyman Spectra; Neutral Particles; Radial Velocity; Tables (Data); Astrophysics full text sources ADS | data products SIMBAD (1)