2008/05/22 by M. A. Urbaneja, Miguel A. Urbaneja, R. -P. Kudritzki +9 · 4 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Blue supergiant #Distance modulus #Galaxies: Formation, Evolution, Phenomena #Galaxy #Local Group #Metallicity #Resolution (logic) #Spectral line #Spectroscopy #Stellar, planetary, and galactic studies #Supergiant #astro-ph
paper · pdf · doi:10.1086/590334
46 pages, 14 figures (2 low resolution color figures). Accepted for publication by ApJ
arxiv created 2008/05/22 · openalex publication_date 2008/08/26 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The quantitative analysis of low-resolution spectra of A and B supergiants is used to determine a distance modulus of 24.99 ± 0.10 mag (995 ± 46 kpc) to the Local Group galaxy WLM. The analysis yields stellar effective temperatures and gravities, which provide a distance through the flux-weighted gravity-luminosity relationship (FGLR). Our distance is 0.07 mag larger than the most recent results based on Cepheids and the tip of the red giant branch. This difference is within the 1 σ overlap of the typical uncertainties quoted in these photometric investigations. In addition, non-LTE spectral synthesis of the rich metal-line spectra (mostly iron, chromium, and titanium) of the A supergiants is carried out, which allows the determination of stellar metallicities. An average metallicity of –0.87 ± 0.06 dex with respect to solar metallicity is found.