Metallicity of M dwarfs. IV. A high-precision [Fe/H] and Teff technique from high-resolution optical spectra for M dwarfs
Aims: In this work we develop a technique to obtain high precision determinations of both metallicity and effective temperature of M dwarfs in the optical.
Methods: A new method is presented that makes use of the information of 4104 lines in the 530-690 nm spectral region. It consists in the measurement of pseudo equivalent widths and their correlation with established scales of [Fe/H] and Teff.
Results: Our technique achieves a rms of 0.08 ± 0.01 for [Fe/H], 91 ± 13 K for Teff, and is valid in the (-0.85,0.26 dex), (2800, 4100 K), and (M0.0, M5.0) intervals for [Fe/H], Teff and spectral type respectively. We also calculated the RMSEV which estimates uncertainties of the order of 0.12 dex for the metallicity and of 293 K for the effective temperature. The technique has an activity limit and should only be used for stars with log LHα/Lbol< - 4.0.
Astronomy and Astrophysics
- Pub Date:
- August 2014
- stars: atmospheres;
- stars: fundamental parameters;
- stars: late-type;
- stars: low-mass;
- methods: data analysis;
- Astrophysics - Solar and Stellar Astrophysics
- Accepted in Astronomy and Astrophysics. Updated one important reference in the introduction. Some typos corrected