Determinação automática dos parâmetros atmosféricos a partir de espectros estelares

Abstract

Stellar parameterization has brought a series of advances to Stellar Astrophysics, but determining physical parameters with good precision is a very complex problem. Most of these physical parameters are obtained directly from the spectral analysis. This analysis is made from different measurements in the stellar spectrum. The main one is the measurement of the equivalent width (LE) of metallic lines. The most common procedure for measuring the LEs of spectral lines is to use interactive routines in the IRAF. Currently, there are a large number of computational codes that assist in the determination of fundamental physical parameters of the stellar atmosphere, such as: MOOG, SPECTRUM, Turbospectrum, among others. These programs, however, are developed to perform specific tasks and none of them performs the entire process of spectral synthesis and the obtainment of atmospheric parameters. In this work, we present a unique and precise automatic tool that we created and will be used in the determination of fundamental physical parameters of the stellar atmosphere, such as effective temperature, surface gravity, microturbulent speed and metallicity. The tool may considerably decrease the time required for the physical characterization of a sample of stars. With this tool in hand, we applied the spectral synthesis technique to a sample of stars evolved from the NGC 2345 star cluster.