English

Korg: a modern 1D LTE spectral synthesis package

Solar and Stellar Astrophysics 2023-02-01 v1 Instrumentation and Methods for Astrophysics

Abstract

We present Korg, a new package for 1D LTE (local thermodynamic equilibrium) spectral synthesis of FGK stars, which computes theoretical spectra from the near-ultraviolet to the near-infrared, and implements both plane-parallel and spherical radiative transfer. We outline the inputs and internals of Korg, and compare synthetic spectra from Korg, MOOG, Turbospectrum, and SME. The disagreements between Korg and the other codes are no larger than those between the other codes, although disagreement between codes is substantial. We examine the case of a C2_2 band in detail, finding that uncertainties on physical inputs to spectral synthesis account for a significant fraction of the disagreement. Korg is 1-100 times faster than other codes in typical use, compatible with automatic differentiation libraries, and easily extensible, making it ideal for statistical inference and parameter estimation applied to large data sets. Documentation and installation instructions are available at https://ajwheeler.github.io/Korg.jl/stable/.

Cite

@article{arxiv.2211.00029,
  title  = {Korg: a modern 1D LTE spectral synthesis package},
  author = {Adam J. Wheeler and Matthew W. Abruzzo and Andrew R. Casey and Melissa K. Ness},
  journal= {arXiv preprint arXiv:2211.00029},
  year   = {2023}
}

Comments

to appear in ApJ; comments welcome

R2 v1 2026-06-28T04:52:46.195Z