TheGaiaFGK benchmark stars

Abstract

Context. An increasing number of high-resolution stellar spectra is available today thanks to many past and ongoing spectroscopic surveys. Consequently, numerous methods have been developed to perform an automatic spectral analysis on a massive amount of data. When reviewing published results, biases arise and they need to be addressed and minimized. Aims. We are providing a homogeneous library with a common set of calibration stars (known as the Gaia FGK benchmark stars) that will allow us to assess stellar analysis methods and calibrate spectroscopic surveys. Methods. High-resolution and signal-to-noise spectra were compiled from different instruments. We developed an automatic process to homogenize the observed data and assess the quality of the resulting library. Results. We built a high-quality library that will facilitate the assessment of spectral analyses and the calibration of present and future spectroscopic surveys. The automation of the process minimizes the human subjectivity and ensures reproducibility. Additionally, it allows us to quickly adapt the library to specific needs that can arise from future spectroscopic analyses.

TheGaia-ESO Survey: radial metallicity gradients and age-metallicity relation of stars in the Milky Way disk

“…The number of stars observed in iDR1 is too small to draw rigorous conclusions. While there is no independent information for the majority of the UVES stars, we can use the library of FGK Benchmark stars, which was built for the Gaia-ESO survey (Jofre et al 2014;Blanco-Cuaresma et al 2014;Heiter et al, in prep.). We have compared the masses from BeSPP for the reference parameters with independent values derived from astero-seismic analysis (available for 12 stars).…”

TheGaiamission

“…The main aim of Gaia is to measure the three-dimensional spatial and the three-dimensional velocity distribution of stars and to determine their astrophysical properties, such as surface gravity and effective temperature, to map and understand the formation, structure, and past and future evolution of our Galaxy (see the review by Bland-Hawthorn & Gerhard 2016). The Milky Way contains a complex mix of stars (and planets), interstellar gas and dust, and dark matter.…”

Climbing the cosmic ladder with stellar twins

“…We carefully normalised the spectra, corrected for the radial velocities of each star, removed telluric absorption, and resampled the spectra to a common wavelength range using the tools described in Blanco-Cuaresma et al (2014b). This was done homogeneously in order to ensure that the relative comparison of the spectra is as objective as possible.…”

“…The normalisation was done by fitting splines of second order locally to the spectra as described in Blanco-Cuaresma et al (2014b). The radial velocity correction was done by crosscorrelating the spectra against a template rest-frame.…”

“…Otherwise if the star had B − V > 1.0 mag, then the star is probably a giant and the template of Arcturus was more suitable for the cross-correlation. Both atlases are included with the tools to prepare the library of Blanco-Cuaresma et al (2014b).…”