New Teff and [Fe/H] spectroscopic calibration for FGK dwarfs and GK giants

Abstract

The ever-growing number of large spectroscopic survey programs has increased the importance of fast and reliable methods with which to determine precise stellar parameters. Some of these methods are highly dependent on correct spectroscopic calibrations. The goal of this work is to obtain a new spectroscopic calibration for a fast estimate of Teff and [Fe/H] for a wide range of stellar spectral types. We used spectra from a joint sample of 708 stars, compiled from 451 FGK dwarfs and 257 GK-giant stars. We used homogeneously determined spectroscopic stellar parameters to derive temperature calibrations using a set of selected EW line-ratios, and [Fe/H] calibrations using a set of selected FeI lines. We have derived 322 EW line-ratios and 100 FeI lines that can be used to compute Teff and [Fe/H], respectively. We show that these calibrations are effective for FGK dwarfs and GK-giant stars in the following ranges: 4500 K < Teff < 6500 K , 2.5 < logg < 4.9 dex, and -0.8 < [Fe/H] < 0.5 dex. The new calibration has a standard deviation of 74 K for Teff and 0.07 dex for [Fe/H]. We use four independent samples of stars to test and verify the new calibration, a sample of 56 giant stars, a sample composed of Gaia FGK benchmark stars, a sample of 36 GK-giant stars of the DR1 of the Gaia-ESO survey, and a sample of 582 FGK-dwarf stars. We also provide a new computer code, GeTCal, for automatically producing new calibration files based on any new sample of stars.

arXiv commentAccepted by A&A for publication, 8 pages, 9 figures

References in corpus (19)

• Exploring the Milky Way stellar disk. A detailed elemental abundance study of 714 F and G dwarf stars in the Solar neighbourhood
• The Radial Velocity Experiment (RAVE): first data release
• An absolutely calibrated effective temperature scale from the InfraRed Flux Method
• Spectroscopic parameters for 451 stars in the HARPS GTO planet search program. Stellar [Fe/H] and the frequency of exo-Neptunes
• Asteroseismic fundamental properties of solar-type stars observed by the NASA Kepler Mission
• A new code for automatic determination of equivalent widths: Automatic Routine for line Equivalent widths in stellar Spectra (ARES)
• Gaia FGK Benchmark Stars - Metallicity
• Gaia FGK Benchmark Stars: Effective temperatures and surface gravities
• Spectroscopic stellar parameters for 582 FGK stars in the HARPS volume-limited sample. Revising the metallicity-planet correlation
• Fundamental Properties of Stars using Asteroseismology from Kepler & CoRoT and Interferometry from the CHARA Array
• ARES v2 - new features and improved performance
• Deriving precise parameters for cool solar-type stars. Optimizing the iron line list
• New and updated stellar parameters for 71 evolved planet hosts. On the metallicity - giant planet connection
• High precision effective temperatures for 181 F--K dwarfs from line-depth ratios
• Metallicities for 13 nearby open clusters from high-resolution spectroscopy of dwarf and giant stars. Stellar metallicity, stellar mass, and giant planets
• An Effective temperature calibration for solar type stars using equivalent width ratios - A fast and easy spectroscopic temperature estimation
• Determination of the spectroscopic stellar parameters for 257 field giant stars
• TMCalc - A fast code to derive Teff and [Fe/H] for FGK stars
• GALAH Survey: Chemically Tagging the Thick Disk

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