Gaia FGK Benchmark Stars: Selecting Infrared Lines for Abundance Determination

Abstract

The advent of new and more powerful infrared spectrographs has significantly motivated the advancement of the study of atomic and molecular line lists and stellar atmosphere models. While optical abundance determinations rely on extensively validated line lists and modeling frameworks, infrared measurements still face larger uncertainties, largely driven by the choice of atmospheric models and the quality of the available atomic data. In this work, we aim to deliver a homogeneous and reproducible set of atomic absorption lines in the Y, J, and H bands (9800 - 18000 (Angstrom)), based exclusively on laboratory atomic data. We analyse CRIRES spectra of six Gaia FGK Benchmark Stars spanning a wide range in effective temperature, surface gravity, and chemical composition. Synthetic spectra are computed using the benchmark stellar parameters, and each transition is evaluated independently in every star through a quantitative sequence that examines line depth, saturation, blending (purity), and the agreement between observed and synthetic line profiles. We identify a set of robust atomic transitions in these bands that remain consistent across the full range of stellar parameters represented in our sample. Lines of alpha-elements such as Mg I, Si I, and Ca I, together with several Fe I transitions, satisfy all robustness criteria. Among the neutron-capture species explored, only Sr II provides lines that consistently meet our requirements. Beyond the specific list of accepted transitions, this study demonstrates that a fully quantitative, multi-criteria framework provides a transparent and reproducible foundation for near-infrared line validation as laboratory data, stellar atmosphere models, and instrumentation continue to improve.

arXiv comment22 pages, 7 figures

References in corpus (46)

• A grid of MARCS model atmospheres for late-type stars I. Methods and general properties
• The Apache Point Observatory Galactic Evolution Experiment (APOGEE)
• A Method of Correcting Near-Infrared Spectra for Telluric Absorption
• Molecfit: A general tool for telluric absorption correction. I. Method and application to ESO instruments
• ASPCAP: The Apogee Stellar Parameter and Chemical Abundances Pipeline
• Automated data reduction workflows for astronomy
• Chemical Cartography with APOGEE: Metallicity Distribution Functions and the Chemical Structure of the Milky Way Disk
• Determining stellar atmospheric parameters and chemical abundances of FGK stars with iSpec
• The James Webb Space Telescope Mission
• NLTE line formation of Fe in late-type stars II: 1D spectroscopic stellar parameters
• Gaia FGK Benchmark Stars - Metallicity
• An atmospheric radiation model for Cerro Paranal. I. The optical spectral range
• Gaia FGK Benchmark Stars: Effective temperatures and surface gravities
• A non-LTE study of neutral and singly-ionized iron line spectra in 1D models of the Sun and selected late-type stars
• The APOGEE red-clump catalog: Precise distances, velocities, and high-resolution elemental abundances over a large area of the Milky Way's disk
• Non-LTE line formation of Fe in late-type stars - III. 3D non-LTE analysis of metal-poor stars
• Atomic data for the Gaia-ESO Survey
• Accuracy and precision of industrial stellar abundances
• From the bulge to the outer disc: StarHorse stellar parameters, distances, and extinctions for stars in APOGEE DR16 and other spectroscopic surveys
• The SDSS-III APOGEE Spectral Line List for H-band Spectroscopy
• Gaia FGK benchmark stars: abundances of alpha and iron-peak elements
• Sulphur and zinc abundances in Galactic halo stars revisited
• The APOGEE Data Release 16 Spectral Line List
• Correcting for Telluric Absorption: Methods, Case Studies, and Release of the TelFit Code
• Non-local thermodynamic equilibrium stellar spectroscopy with 1D and <3D> models - I. Methods and application to magnesium abundances in standard stars
• The GALAH Survey: Non-LTE departure coefficients for large spectroscopic surveys
• Chemical abundances for 11 bulge stars from high-resolution, near-IR spectra
• Systematic NLTE study of the -2.6 < [Fe/H] < 0.2 F and G dwarfs in the solar neighbourhood. I. Stellar atmosphere parameters
• CRIRES${}^{+}$ on sky at the ESO Very Large Telescope
• Sulphur abundance in Galactic stars
• Red Supergiant Stars as Cosmic Abundance Probes: NLTE Effects in J-band Iron and Titanium Lines
• NLTE for APOGEE: Simultaneous Multi-Element NLTE Radiative Transfer
• Gaia FGK Benchmark Stars: New Candidates At Low-Metallicities
• First Stars XIV. Sulfur abundances in extremely metal-poor (EMP) stars
• Abundances in bulge stars from high-resolution, near-IR spectra I. The CNO elements observed during the science verification of CRIRES at VLT
• Detailed abundances in the Galactic center: Evidence of a metal-rich alpha-enhanced stellar population
• The Chemical Compositions of Very Metal-Poor Stars HD 122563 and HD 140283; A View From the Infrared
• Telluric correction in the near-infrared: Standard star or synthetic transmission?
• Correction of near-infrared high-resolution spectra for telluric absorption at 0.90-1.35 microns
• FeI lines in 0.91-1.33 $\mu$m spectra of red giants for measuring the microturbulence and metallicities
• Determination of small-scale magnetic fields on Sun-like stars in the near-infrared using CRIRES${}^{+}$
• Stellar atmospheric parameters of FGK-type stars from high-resolution optical and near-infrared CARMENES spectra
• Identification of Absorption Lines of Heavy Metals in the Wavelength Range 0.97--1.32 Micron
• F, G, K, M Spectral Standards in the Y Band (0.95-1.11 um)
• Gaia FGK Benchmark Stars: spectral library, metallicities and abundances of $\alpha$ and Fe-peak elements of the third version
• A First Study of Giant Stars in the Galactic Bulge based on Crires spectra