2007/10/17 by Henry Thompson, H. M. A. Thompson, F. P. Keenan +4 · 2 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2007.12597.x
3 figures and 8 tables. Table 3 is to be published online only (included here on last page). Accepted for publication in MNRAS
arxiv created 2007/10/17 · openalex publication_date 2007/12/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/01
Abstract The role of optical Fe iii absorption lines in B-type stars as iron abundance diagnostics is considered. To date, ultraviolet Fe lines have been widely used in B-type stars, although line blending can severely hinder their diagnostic power. Using optical spectra, covering a wavelength range ∼3560–9200 Å, a sample of Galactic B-type main-sequence and supergiant stars of spectral types B0.5 to B7 are investigated. A comparison of the observed Fe iii spectra of supergiants, and those predicted from the model atmosphere codes tlusty[plane-parallel, non-local thermodynamic equilibrium (LTE)], with spectra generated using synspec (LTE), and cmfgen (spherical, non-LTE), reveal that non-LTE effects appear small. In addition, a sample of main-sequence and supergiant objects, observed with the Fiber-fed Extended Range Optical Spectrograph (FEROS), reveal LTE abundance estimates consistent with the Galactic environment and previous optical studies. Based on the present study, we list a number of Fe iii transitions which we recommend for estimating the iron abundance from early B-type stellar spectra.