Spectral Implications of Atomic Uncertainties in Optically-thin Hot Plasmas

TL;DR

This paper develops methods to estimate how uncertainties in atomic data affect X-ray spectral models of optically-thin hot plasmas, crucial for interpreting upcoming high-resolution X-ray observations from XRISM and Athena.

Contribution

It introduces an extension to the pyatomdb code that quantifies the impact of atomic data uncertainties on spectral line predictions.

Findings

Uncertainties significantly affect key diagnostic lines.

The methods enable better interpretation of high-resolution spectra.

Sensitivity varies across different atomic transitions.

Abstract

Two new high-resolution X-ray spectroscopy missions, XRISM and Athena, will observe deeper and with higher X-ray resolution than ever before possible. Interpreting these new X-ray spectra will require understanding the impact that uncertainties on fundamental atomic quantities such as collisional cross sections, transition rates, and wavelengths have on spectral models. As millions of values are required to generate even a simple model of an optically-thin hot plasma, most such rates exist only as theoretical calculations. We have developed methods to estimate the uncertainty in the final spectral calculations based on published experimental data and plausible approximations to the uncertainties in the underlying atomic data. We present an extension to the pyatomdb code that implements these methods and investigate the sensitivity of selected strong diagnostic lines in the X-ray bandpass (0.3-12 keV).