1D non-LTE corrections for chemical abundance analyses of very metal-poor stars

TL;DR

This paper provides 1D non-LTE abundance correction grids for key elements in very metal-poor stars, aiding homogeneous chemical abundance analysis in galactic archaeology.

Contribution

It introduces comprehensive grids of 1D-NLTE corrections for multiple elements across a wide range of stellar parameters, facilitating more accurate abundance determinations.

Findings

Grids cover T_eff 4000-6500K, log g 0.5-5.0, [Fe/H] -5.0 to -2.0.

Data is publicly available with online interpolation tools.

Enhances the accuracy of chemical abundance analyses in VMP stars.

Abstract

Detailed chemical abundances of very metal-poor (VMP, [Fe/H] < -2) stars are important for better understanding the First Stars, early star formation and chemical enrichment of galaxies. Big on-going and coming high-resolution spectroscopic surveys provide a wealth of material that needs to be carefully analysed. For VMP stars, their elemental abundances should be derived based on the non-local thermodynamic equilibrium (non-LTE = NLTE) line formation because low metal abundances and low electron number density in the atmosphere produce the physical conditions favorable for the departures from LTE. The galactic archaeology research requires homogeneous determinations of chemical abundances. For this purpose, we present grids of the 1D-NLTE abundance corrections for the Na I, Mg I, Ca I, Ca II, Ti II, Fe I, Zn I, Zn II, Sr II, and Ba II lines, which are used in the galactic archaeology research. The range of atmospheric parameters represents VMP stars on various evolutionary stages and covers effective temperatures from 4000 to 6500~K, surface gravities from log g = 0.5 to log g = 5.0, and metallicities $-5.0 \le$ [Fe/H] $\le -2.0$. The data is publicly available, and we provide the tools for interpolating in the grids online.