An Effective temperature calibration for solar type stars using equivalent width ratios - A fast and easy spectroscopic temperature estimation

TL;DR

This paper introduces a rapid, automatic method for estimating the effective temperature of solar-type stars using calibrated ratios of spectral line equivalent widths, enhancing precision and efficiency in stellar characterization.

Contribution

It provides a new calibration for effective temperature based on 433 line ratios from 171 spectral lines, along with a free tool for automatic temperature estimation.

Findings

Calibration based on 433 line ratios for 171 spectral lines.

The method enables fast and automatic temperature estimation.

The calibration improves precision in stellar temperature measurements.

Abstract

Aims: The precise determination of the stellar effective temperature of solar type stars is of extreme importance for Astrophysics. We present an effective temperature calibration for FGK dwarf stars using line equivalent width ratios of spectral absorption lines. Method: The ratios of spectral line equivalent width can be very sensitive to effective temperature variations for a well chosen combination of lines. We use the automatic code ARES to measure the equivalent width of several spectral lines, and use these to calibrate with the precise effective temperature derived from spectroscopy presented in a previous work. Results: We present the effective temperature calibration for 433 line equivalent width ratios built from 171 spectral lines of different chemical elements. We also make available a free code that uses this calibration and that can be used as an extension to ARES for the fast and automatic estimation of spectroscopic effective temperature of solar type stars.