TY - JOUR
T1 - An extended and refined grid of 3D STAGGER model atmospheres
T2 - Processed snapshots for stellar spectroscopy
AU - Rodríguez Díaz, Luisa F.
AU - Lagae, Cis
AU - Amarsi, Anish M.
AU - Bigot, Lionel
AU - Zhou, Yixiao
AU - Aguirre Børsen-Koch, Víctor
AU - Lind, Karin
AU - Trampedach, Regner
AU - Collet, Remo
N1 - Publisher Copyright:
© The Authors 2024.
PY - 2024/8/23
Y1 - 2024/8/23
N2 - Context. Traditional one-dimensional hydrostatic model atmospheres introduce systematic modelling errors into spectroscopic analyses of FGK-Type stars. Aims. We present an updated version of the STAGGER-grid of three-dimensional model atmospheres, and explore the accuracy of postprocessing methods in preparation for spectral synthesis. Methods. New and old models were (re)computed following an updated workflow, including an updated opacity binning technique. Spectroscopic tests were performed in three-dimensional local thermodynamic equilibrium for a grid of 216 fictitious Fe I lines, spanning a wide range of oscillator strengths, excitation potentials, and central wavelengths, and eight model atmospheres that cover the stellar atmospheric parameter range (Teff, log g, and [Fe/H]) of FGK-Type stars. Using this grid, the impact of vertical and horizontal resolutions, and temporal sampling of model atmospheres on spectroscopic diagnostics, was tested. Results. We find that downsampling the horizontal mesh from its original size of 240 × 240 grid cells to 80 × 80 cells, in other words, sampling every third grid cell, introduces minimal errors on the equivalent width and normalised line flux across the line and stellar parameter space. Regarding temporal sampling, we find that sampling ten statistically independent snapshots is sufficient to accurately model the shape of spectral line profiles. For equivalent widths, a subsample consisting of only two snapshots is sufficient, introducing an abundance error of less than 0.015 dex. Conclusions. We have computed 32 new model atmospheres and recomputed 116 old ones present in the original grid. The public release of the STAGGER-grid contains 243 models and the processed snapshots can be used to improve the accuracy of spectroscopic analyses.
AB - Context. Traditional one-dimensional hydrostatic model atmospheres introduce systematic modelling errors into spectroscopic analyses of FGK-Type stars. Aims. We present an updated version of the STAGGER-grid of three-dimensional model atmospheres, and explore the accuracy of postprocessing methods in preparation for spectral synthesis. Methods. New and old models were (re)computed following an updated workflow, including an updated opacity binning technique. Spectroscopic tests were performed in three-dimensional local thermodynamic equilibrium for a grid of 216 fictitious Fe I lines, spanning a wide range of oscillator strengths, excitation potentials, and central wavelengths, and eight model atmospheres that cover the stellar atmospheric parameter range (Teff, log g, and [Fe/H]) of FGK-Type stars. Using this grid, the impact of vertical and horizontal resolutions, and temporal sampling of model atmospheres on spectroscopic diagnostics, was tested. Results. We find that downsampling the horizontal mesh from its original size of 240 × 240 grid cells to 80 × 80 cells, in other words, sampling every third grid cell, introduces minimal errors on the equivalent width and normalised line flux across the line and stellar parameter space. Regarding temporal sampling, we find that sampling ten statistically independent snapshots is sufficient to accurately model the shape of spectral line profiles. For equivalent widths, a subsample consisting of only two snapshots is sufficient, introducing an abundance error of less than 0.015 dex. Conclusions. We have computed 32 new model atmospheres and recomputed 116 old ones present in the original grid. The public release of the STAGGER-grid contains 243 models and the processed snapshots can be used to improve the accuracy of spectroscopic analyses.
KW - Convection
KW - Hydrodynamics
KW - Radiative transfer
KW - Stars: Abundances
KW - Stars: Atmospheres
U2 - 10.1051/0004-6361/202348480
DO - 10.1051/0004-6361/202348480
M3 - Journal article
AN - SCOPUS:85202036182
VL - 688
JO - Astronomy & Astrophysics
JF - Astronomy & Astrophysics
SN - 0004-6361
M1 - A212
ER -