Spectral Implications of Atomic Uncertainties in Optically Thin Hot Plasmas

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 which implements these methods and investigate the sensitivity of selected strong diagnostic lines in the X-ray bandpass (0.3-12 keV).

Automated summary

The new high-resolution X-ray spectroscopy missions, XRISM and Athena, will observe deeper and with higher X-ray resolution than ever before. Understanding the impact of uncertainties on fundamental atomic quantities such as collisional cross sections, transition rates, and wavelengths on spectral models is crucial for interpreting these new X-ray spectra. Methods have been developed to estimate uncertainty in final spectral calculations based on experimental data and plausible approximations to uncertainties in underlying atomic data.