Astronomy and Astrophysics – Astrophysics
Scientific paper
Jul 1985
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1985apjs...58..379w&link_type=abstract
Astrophysical Journal Supplement Series (ISSN 0067-0049), vol. 58, July 1985, p. 379-411. NSERC-supported research.
Astronomy and Astrophysics
Astrophysics
134
Stellar Atmospheres, Stellar Spectra, Stellar Spectrophotometry, Ultraviolet Spectra, White Dwarf Stars, Iue, Spectral Energy Distribution, Star Distribution, Stellar Composition, Stellar Models, Stellar Temperature
Scientific paper
Recent optical and spectrophotometric observations of all currently known DAO and DO hot white dwarf candidates from the Palomar-Green Survey are presented. The optical observations were carried out using the Kitt Peak National Observatory Intensified Image Dissector Scanner (IIDS) system, the Multiple Mirror Telescope (MMT), and two photon-counting Reticon systems. Ultraviolet spectrophotometry was obtained using the International Ultraviolet Explorer (IUE) short-wavelength and long-wavelength cameras. The following spectroscopic subgroups were identified in the observations: the cool DO stars with spectra showing H I features together with He II + H blends; the hot DO stars, with spectra exhibiting weak He II (+H) lines; and hydrogen-rich DAO stars with broad H lines and sharp H II lines at 4686 A. A fourth subgroup of stars resembling PG 1159 with He at He II lines at 4686, and a C, N ion blend in the optical spectrum were also found. The spectroscopic data were analyzed in terms of a grid of hot, high-gravity LTE model atmospheres composed of a mixture of hydrogen and helium, and atmospheric parameters are deduced for each class of objects. On the basis of the model atmosphere analysis, the local space density of the DO stars is estimated to be 1.9-3.0 x 10 to the -7th per cubic pc, depending on the scale height.
Green Richard F.
Liebert James
Wesemael François
No associations
LandOfFree
Spectrophotometric and model-atmosphere analyses of the hot DO and DAO white dwarfs from the Palomar-Green survey does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Spectrophotometric and model-atmosphere analyses of the hot DO and DAO white dwarfs from the Palomar-Green survey, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Spectrophotometric and model-atmosphere analyses of the hot DO and DAO white dwarfs from the Palomar-Green survey will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1231409