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Record 1 of 779
A non-local thermodynamic equilibrium, line-blanketed synthetic spectrum of Iota Herculis - C, Al, and Si lines
External Online Source: doi:10.1086/170617
Author and Affiliation:
Grigsby, James A.(NASA Goddard Space Flight Center, Greenbelt, MD, United States)
Abstract: A non-LTE line-blanketed model stellar atmosphere is used to compute a model of I Herculis (B3 IV) with a Teff of 17,500 K and a log g of 3.75, following the conclusions of Peters and Polidan (1985). Detailed profiles of a number of lines of C, Al, and Si in the 1200-2000-A region are computed, including the resonance lines of C II, Al II, and Al III. These profiles are compared to observations obtained from the coaddition of eight IUE SWP images, using a technique developed by Leckrone and Adelman (1989). Comparison of carbon lines with a model that is underabundant in carbon by a factor of 2 relative to the sun indicates that the C abundance of Iota Her is at most one-half solar. Non-LTE effects are examined by comparing an LTE model possessing identical atmospheric parameters with the non-LTE model. Substantial differences in the populations of the model atomic states are found, but differences in the temperature structure of the two models often mask the non-LTE effects in the synthetic spectra.
Publication Date: Oct 20, 1991
Document ID:
19910072256
(Acquired Nov 28, 1995)
Accession Number: 91A56879
Subject Category: ASTROPHYSICS
Document Type: Journal Article
Publication Information: Astrophysical Journal, Part 1 (ISSN 0004-637X); 380; 606-616
Publisher Information: United States
Financial Sponsor: NASA; United States
Organization Source: NASA Goddard Space Flight Center; Greenbelt, MD, United States
Description: 11p; In English
Distribution Limits: Unclassified; Publicly available; Unlimited
Rights: Copyright
NASA Terms: B STARS; EARLY STARS; MAIN SEQUENCE STARS; STELLAR ATMOSPHERES; STELLAR SPECTRA; THERMODYNAMIC EQUILIBRIUM; ABUNDANCE; ALUMINUM; CARBON; RESONANCE LINES; SILICON; STELLAR MODELS
Imprint And Other Notes: Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 380, Oct. 20, 1991, p. 606-616. Research supported by National Research Council.
Miscellaneous Notes: Research supported by National Research Council
Availability Source: Other Sources
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