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Centro de Astrofísica da Universidade do Porto

A new code for automatic determination of equivalent widths: Automatic Routine for line Equivalent widths in stellar Spectra (ARES)

S. G. Sousa, N. C. Santos, G. Israelian, M. Mayor, M. J. P. F. G. Monteiro

Abstract
Aims. We present a new automatic code (ARES) for determining equivalent widths of the absorption lines present in stellar spectra. We also describe its use for determining fundamental spectroscopic stellar parameters.
Methods. The code is written in C++ based on the standard method of determining EWs and is available for the community. The code automates the manual procedure that the users normally carry out when using interactive routines such as the splot routine implemented in IRAF.
Results. We test the code using both simulated and real spectra with different levels of resolution and noise and comparing its measurements to the manual ones obtained in the standard way. The results shows a small systematic difference, always below 1.5mÅ. This can be explained by errors in the manual measurements caused by subjective continuum determination. The code works better and faster than others tested before.

Keywords
methods: data analysis – techniques: spectroscopic – stars: abundances – stars: fundamental parameters

Astronomy and Astrophysics
Volume 469, Page 783
July 2007

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