Volume 538, February 2012
|Number of page(s)||13|
|Section||Catalogs and data|
|Published online||16 February 2012|
Stellar population models in the UV
I. Characterisation of the New Generation Stellar Library⋆
1 Instituto de Astrofísica de Canarias, La Laguna, 38200 Tenerife, Spain
2 Departamento de Astrofísica, Universidad de La Laguna, 38205 La Laguna, Tenerife, Spain
3 Université Lyon 1, Villeurbanne, 69622, France; CRAL, Observatoire de Lyon, 69561, St. Genis Laval, CNRS, UMR 5574, France
4 Sterrenkundig Observatorium, Ghent University, Krijgslaan 281, S9, 9000 Ghent, Belgium
Received: 10 September 2011
Accepted: 27 October 2011
Context. The spectral predictions of stellar population models are not as accurate in the ultra-violet (UV) as in the optical wavelength domain. One of the reasons is the lack of high-quality stellar libraries. The New Generation Stellar Library (NGSL), recently released, represents a significant step towards the improvement of this situation.
Aims. To prepare NGSL for population synthesis, we determined the atmospheric parameters of its stars, we assessed the precision of the wavelength calibration and characterised its intrinsic resolution. We also measured the Galactic extinction for each of the NGSL stars.
Methods. For our analyses we used ULySS, a full spectrum fitting package, fitting the NGSL spectra against the MILES interpolator.
Results. We find that the wavelength calibration is precise up to 0.1 px, after correcting a systematic effect in the optical range. The spectral resolution varies from 3 Å in the UV to 10 Å in the near-infrared (NIR), corresponding to a roughly constant reciprocal resolution R = λ/δλ ≈ 1000 and an instrumental velocity dispersion σins ≈ 130 km s-1. We derived the atmospheric parameters homogeneously. The precision for the FGK stars is 42 K, 0.24 and 0.09 dex for Teff, log g and [Fe/H], respectively. The corresponding mean errors are 29 K, 0.50 and 0.48 dex for the M stars, and for the OBA stars they are 4.5 percent, 0.44 and 0.18 dex. The comparison with the literature shows that our results are not biased.
Key words: methods: data analysis / stars: fundamental parameters
Table A1 is only available at CDS via anonymous ftp to cdsarc.u-strasbg.fr (188.8.131.52) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/538/A143
© ESO, 2012
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.