A new procedure for defining a homogenous line-list for solar-type stars^⋆

¹ Centro de Astrofísica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto, Portugal
e-mail: sousasag@astro.up.pt
² Departamento de Física e Astronomia, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal
³ Dpto. de Astrofísica, Facultad de CC. Fisicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
⁴ Instituto de Astrofisica de Canarias, Cl. via Lactea s/n, 38200 La Laguna, Tenerife, Spain
⁵ Dept. Astrofisica, Universidad de La Laguna (ULL), 38206 La Laguna, Tenerife, Spain
⁶ European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching bei München, Germany
⁷ Department for Astrophysics, Nicolaus Copernicus Astronomical Center, ul. Rabiańska 8, 87-100 Toruń, Poland
⁸ Department of Physics and Astronomy, Division of Astronomy and Space Physics, Uppsala University, Box 516, 75120 Uppsala, Sweden
⁹ Max Planck Institute for Astrophysics, Karl-Schwarzschild str. 1, 85741 Garching, Germany
¹⁰ Université de Bordeaux 1, CNRS Laboratoire d’Astrophysique de Bordeaux, UMR 5804, BP 89, 33271 Floirac Cedex, France
¹¹ Laboratoire Lagrange (UMR 7293), Université de Nice Sophia Antipolis, CNRS, Observatoire de la Côte d’Azur, BP 4229, 06304 Nice Cedex 04, France
¹² Institute of Theoretical Physics and Astronomy, Vilnius University, Goštauto 12, 01108 Vilnius, Lithuania

Received: 16 July 2013
Accepted: 20 November 2013

Abstract

Context. The homogenization of the stellar parameters is an important goal for large observational spectroscopic surveys, but it is very difficult to achieve it because of the diversity of the spectroscopic analysis methods used within a survey, such as spectrum synthesis and the equivalent width method. To solve this problem, constraints to the spectroscopic analysis can be set, such as the use of a common line-list.

Aims. We present a procedure for selecting the best spectral lines from a given input line-list, which then allows us to derive accurate stellar parameters with the equivalent width method.

Methods. To select the lines, we used four very well known benchmark stars, for which we have high-quality spectra. From an initial line-list, the equivalent width of each individual line was automatically measured for each benchmark star using ARES, then we performed a local thermodynamic equilibrium analysis with MOOG to compute individual abundances. The results allowed us to choose the best lines, which give consistent abundance values for all the benchmark stars from which we then created a final line-list.

Results. To verify its consistency, the compiled final line-list was tested for a small sample of stars. These stars were selected to cover different ranges in the parameter space for FGK stars. We show that the obtained parameters agree well with previously determined values.