Comparative analysis of atmospheric parameters from high-resolution spectroscopic sky surveys: APOGEE, GALAH, Gaia-ESO

TL;DR

This study compares atmospheric parameters and elemental abundances from APOGEE, GALAH, and Gaia-ESO sky surveys, revealing generally good agreement but also identifying significant offsets and trends in certain regimes.

Contribution

It provides a detailed comparison of the most recent data releases of three major sky surveys, assessing their accuracy, precision, and systematic differences in stellar parameters.

Findings

Good overall agreement in radial velocities and atmospheric parameters.

Identification of large radial velocity scatters between surveys.

Detection of specific elemental abundance correlations and offsets.

Abstract

SDSS-IV APOGEE-2, GALAH and Gaia-ESO are high resolution, ground-based, multi-object spectroscopic surveys providing fundamental stellar atmospheric parameters and multiple elemental abundance ratios for hundreds of thousands of stars of the Milky Way. We undertake a comparison between the most recent data releases of these surveys to investigate the accuracy and precision of derived parameters by placing the abundances on an absolute scale. We discuss the correlations in parameter and abundance differences as a function of main parameters. Uncovering the variants provides a basis to on-going efforts of future sky surveys. Quality samples from the APOGEE-GALAH, APOGEE-GES and GALAH-GES overlapping catalogs are collected. We investigate the mean variants between the surveys, and linear trends are also investigated. We compare the slope of correlations and mean differences with the reported uncertainties. The average and scatter of vrad, Teff, log g, [M/H] and vmicro, along with numerous species of elemental abundances in the combined catalogs show that in general there is a good agreement between the surveys. We find large radial velocity scatters ranging from 1.3 km/s to 4.4 km/s when comparing the three surveys. We observe weak trends: e.g. in $\Delta$Teff vs. $\Delta$log g for the APOGEE-GES stars, and a clear correlation in the vmicro-$\Delta$vmicro planes in the APOGEE-GALAH common sample. For [$\alpha$/H], [Ti/H] (APOGEE-GALAH giants) and [Al/H] (APOGEE-GALAH dwarfs) potential strong correlations are discovered as a function of the differences in the main atmospheric parameters, and we find weak trends for other elements. In general we find good agreement between the three surveys within their respective uncertainties. However, there are certain regimes in which strong variants exist, which we discuss. There are still offsets larger than 0.1 dex in the absolute abundance scales.