AAS 201st Meeting, January, 2003
Session 113. Massive Star Winds and Atmospheres
Poster, Thursday, January 9, 2003, 9:20am-4:00pm, Exhibit Hall AB

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[113.11] The Abundances of the Fe Group Elements in the SMC B0.5V Star AV~304 Determined from the Analysis of FUSE Data

G.J. Peters (USC), S.J. Adelman (The Citadel)

We present initial results from an abundance study of AV~304, a sharp-lined B0.5V star in the Small Magellanic Cloud, using recently-acquired spectroscopic data from the Far Ultraviolet Spectroscopic Explorer (FUSE) and the Kurucz LTE model atmosphere/spectrum synthesis codes ATLAS9/SYNTHE. Emphasis is on the abundances of the Fe group elements that do not produce measurable lines in the optical spectral region. A model of \rm Teff = 26,500~K, log~g = 4.0, and [M/H] = -0.5 was adopted based upon a least squares fit to IUE LORES data and the UBV magnitudes for the star. Other input parameters used included \rm Vturb = 1~\rm km~s-1 (from the continuum fit), v~sin~i = 20~\rm km~s-1, and an instrumental broadening parameter of 20,000 corresponding to the spectral resolution of the FUSE LiF channels. A mean Fe abundance, \rm [Fe/H]\odot, of -0.70±0.3 was obtained from \ion{Fe}{3} multiplets UV1 (1122--1132~Å) and UV39 (1142--1144~Å). This agrees well with the value of -0.61±0.30 found from 65 lines of \ion{Fe}{3} in the 1900~Å\, region observed with HST/STIS (Peters & Grigsby 2003, submitted) and also abundances determined from lines in the ISM and A supergiants. The abundance of V from \ion{V}{3} UV2 (1148--1154~Å) appears to be close to the solar value, but more study is warranted. On the other hand, upper limits on the abundances of Cr and Mn from several \ion{Cr}{3} and \ion{Mn}{3} lines in the 1100--1160~Å\, region are 1.0 dex below the solar values. This supports the results from the Peters/Grigsby analysis of HST/STIS spectra in which abundances of -1.00 dex were found for both elements.

GJP appreciates support from NASA grant NAG5-12239.


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