Inversion of Stokes Profiles with Systematic Effects

TL;DR

This paper introduces an extension to spectral line inversion codes that effectively accounts for systematic effects such as blending and telluric absorption, improving the accuracy of plasma property inference in solar and stellar atmospheres.

Contribution

The authors develop a simple, adaptable extension to existing inversion codes that transparently handles systematic effects during spectral analysis.

Findings

Enhanced inversion accuracy in the presence of systematic effects

Easy integration of the extension into existing codes

Applicable to various spectral lines and atmospheric models

Abstract

Quantitative thermodynamical, dynamical and magnetic properties of the solar and stellar plasmas are obtained by interpreting their emergent non-polarized and polarized spectrum. This inference requires the selection of a set of spectral lines particularly sensitive to the physical conditions in the plasma and a suitable parametric model of the solar/stellar atmosphere. Nonlinear inversion codes are then used to fit the model to the observations. However, the presence of systematic effects like nearby or blended spectral lines, telluric absorption or incorrect correction of the continuum, among others, can strongly affect the results. We present an extension to current inversion codes that can deal with these effects in a transparent way. The resulting algorithm is very simple and can be applied to any existing inversion code with the addition of a few lines of code as an extra step in each iteration.