Nitrogen K-shell photoabsorption

TL;DR

This paper presents comprehensive atomic data for nitrogen K lines, including energies, wavelengths, and cross sections, crucial for astrophysical spectral modeling, with a focus on accuracy and damping effects.

Contribution

It provides new, detailed atomic data for nitrogen K lines using advanced calculations, addressing the lack of experimental measurements and improving spectral modeling accuracy.

Findings

Data sets include energies, wavelengths, and cross sections for nitrogen K lines.

Comparison with previous data validates the new calculations.

Inclusion of damping effects enhances the realism of K-edge modeling.

Abstract

Reliable atomic data have been computed for the spectral modeling of the nitrogen K lines, which may lead to useful astrophysical diagnostics. Data sets comprise valence and K-vacancy level energies, wavelengths, Einstein $A$-coefficients, radiative and Auger widths and K-edge photoionization cross sections. An important issue is the lack of measurements which are usually employed to fine-tune calculations so as to attain spectroscopic accuracy. In order to estimate data quality, several atomic structure codes are used and extensive comparisons with previous theoretical data have been carried out. In the calculation of K photoabsorption with the Breit--Pauli $R$-matrix method, both radiation and Auger damping, which cause the smearing of the K edge, are taken into account. This work is part of a wider project to compute atomic data in the X-ray regime to be included in the database of the popular {\sc xstar} modeling code.