Enhanced methods for computing spectra from CO5BOLD models using Linfor3D. Molecular bands in metal-poor stars

TL;DR

This paper discusses improvements to the Linfor3D spectral synthesis code for efficiently computing molecular bands in 3D models of metal-poor stars, which are crucial for abundance analysis.

Contribution

The paper introduces enhanced methods for 3D spectral synthesis with Linfor3D, addressing computational challenges in modeling molecular features in stellar spectra.

Findings

Improved computational efficiency for 3D molecular band synthesis.

Identification of new challenges in 3D molecular feature modeling.

Enhanced accuracy in abundance diagnostics for metal-poor stars.

Abstract

Molecular features such as the G-band, CN-band and NH-band are important diagnostics for measuring a star's carbon and nitrogen abundances, especially in metal-poor stars where atomic lines are no longer visible in stellar spectra. Unlike atomic transitions, molecular features tend to form in bands, which cover large wavelength regions in a spectrum. While it is a trivial matter to compute carbon and nitrogen molecular bands under the assumption of 1D, it is extremely time consuming in 3D. In this contribution to the 2016 CO5BOLD workshop we review the improvements made to the 3D spectral synthesis code Linfor3D, and discuss the new challenges found when computing molecular features in 3D.