The FeH Wing-Ford Band in Spectra of M Stars
Abstract
We study the FeH Wing-Ford band at 9850-10200 Å by fitting synthetic spectra to the observations of M stars, employing recent model atmospheres. On the basis of the spectral synthesis, we analyze the dependence of the band upon atmospheric parameters. FeH lines are a very sensitive surface gravity indicator, being stronger in dwarfs. They are also sensitive to metallicity. The blending with CN lines, which are stronger in giants, does not affect the response of the Wing-Ford band to surface gravity at low resolution (or high velocity dispersions), because CN lines, which are spread all along the spectrum, are smeared out at convolutions of FWHM >~ 3 Å. We conclude that the Wing-Ford band is a suitable dwarf/giant indicator for the study of composite stellar populations.
Observations collected at Laboratório Nacional de Astrofísica, Pico dos Dias, Brazil.- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 1997
- DOI:
- 10.1086/304332
- arXiv:
- arXiv:astro-ph/9701186
- Bibcode:
- 1997ApJ...484..499S
- Keywords:
-
- Infrared: Stars;
- Molecular Data;
- Stars: Fundamental Parameters;
- Stars: Late-Type;
- Astrophysics
- E-Print:
- 23 pages + 11 figures in postscript format + 3 ps figures (Nos. 2, 6 and 7) available under request to ripisc@andromeda.iagusp.usp.br. Accepted for publication in The Astrophysical Journal