Journal article
Goddard high-resolution spectrograph observations of the local interstellar medium and the deuterium/hydrogen ratio along the line of sight toward Capella
The Astrophysical journal, Vol.402(2), pp.694-709
01/10/1993
DOI: 10.1086/172170
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.
Details
- Title: Subtitle
- Goddard high-resolution spectrograph observations of the local interstellar medium and the deuterium/hydrogen ratio along the line of sight toward Capella
- Creators
- Jeffrey L. LinskyAlexander Brown - Goddard Space Flight CenterKen Gayley - Joint Inst. for Lab. AstrophysicsAthanassios Diplas - Goddard Space Flight CenterBlair D. Savage - Wisconsin UnivThomas R. Ayres - Colorado UnivWayne Landsman - Goddard Space Flight CenterSteven N. ShoreSara R. Heap - Goddard Space Flight Center
- Resource Type
- Journal article
- Publication Details
- The Astrophysical journal, Vol.402(2), pp.694-709
- DOI
- 10.1086/172170
- ISSN
- 0004-637X
- eISSN
- 1538-4357
- Language
- English
- Date published
- 01/10/1993
- Description audience
- PUBLIC
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984429046602771