The araucaria project: The local group galaxy WLM-distance and metallicity from quantitative spectroscopy of blue supergiants

Urbaneja, MA; Kudritzki, RP; Bresolin, F; Przybilla, N; Gieren, WG; Pietrzynski G.

Abstract

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. © 2008. The American Astronomical Society. All rights reserved.

Más información

Título según WOS: The araucaria project: The local group galaxy WLM-distance and metallicity from quantitative spectroscopy of blue supergiants
Título según SCOPUS: The araucaria project: The local group galaxy WLM - Distance and metallicity from quantitative spectroscopy of blue supergiants
Título de la Revista: ASTROPHYSICAL JOURNAL
Volumen: 684
Número: 1
Editorial: IOP PUBLISHING LTD
Fecha de publicación: 2008
Página de inicio: 118
Página final: 135
Idioma: English
URL: http://stacks.iop.org/0004-637X/684/i=1/a=118
DOI:

10.1086/590334

Notas: ISI, SCOPUS