Goddard high-resolution spectrograph observations of the local interstellar medium and the deuterium/hydrogen ratio along the line of sight toward Capella

Abstract

view Abstract Citations (285) References (74) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Goddard High-Resolution Spectrograph Observations of the Local Interstellar Medium and the Deuterium/Hydrogen Ratio along the Line of Sight toward Capella Linsky, Jeffrey L. ; Brown, Alexander ; Gayley, Ken ; Diplas, Athanassios ; Savage, Blair D. ; Ayres, Thomas R. ; Landsman, Wayne ; Shore, Steven N. ; Heap, Sara R. Abstract HST Goddard High-Resolution Spectrograph observations of the 1216, 2600, and 2800 A spectral regions are analyzed for the spectroscopic binary system Capella, obtained at orbital phase 0.26 with 3.27-3.57 km/s resolution and high SNR. The column densities of H I, D I, Mg II, and Fe II for the local interstellar medium along this 12.5 pc line of sight, together with estimates of the temperature and turbulent velocity are inferred. It is inferred that the atomic deuterium/hydrogen ratio by number is 1.65(+0.07, -0.18) x 10 exp -5 for this line of sight. Galactic evolution calculations indicate that the primordial D/H ratio probably lies in the range of (1.5-3) x (D/H)LISM. If H0 = 80 km/s Mpc, as recent evidence suggests, then the baryonic density in units of the Einstein-de Sitter closure density is 0.023-0.031. Thus the universe is argued to expand forever, unless nonbaryonic matter greatly exceeds the amount of baryonic matter. Publication: The Astrophysical Journal Pub Date: January 1993 DOI: 10.1086/172170 Bibcode: 1993ApJ...402..694L Keywords: Astronomical Spectroscopy; Binary Stars; Deuterium; Hydrogen; Abundance; Baryons; Galactic Evolution; Line Spectra; Lyman Alpha Radiation; Universe; Astrophysics; ISM: ABUNDANCES; STARS: INDIVIDUAL CONSTELLATION NAME: ALPHA AURIGAE; ULTRAVIOLET: INTERSTELLAR full text sources ADS | data products SIMBAD (11) MAST (2) ESA (1)