A catalogue of Paschen-line profiles in standard stars

TL;DR

This paper presents an atlas of Paschen-line profiles for standard stars, aiding stellar modeling by providing detailed spectral line data across various stellar types and conditions.

Contribution

It compiles and displays a comprehensive catalogue of Paschen-line profiles, including LTE calculations for some stars, to support stellar spectral analysis.

Findings

Profiles vary with stellar type and luminosity

Departures from LTE are significant in high luminosity, cool stars

Sample LTE profiles demonstrate catalogue usefulness

Abstract

We have assembled an atlas of line profiles of the Paschen Delta line at 10,049 angstroms for the use of stellar modelling. For a few stars we have substituted the Paschen Gamma line at 10,938 angstroms because the Paschen Delta line blends with other features. Most of the targets are standard stars of spectral types from B to M. A few metal-poor stars have been included. For many of the stars we have also observed the Hydrogen Alpha line so as to compare the profiles of lines originating from the meta-stable n=2 level with lines originating from the n=3 level. The greatest difference in line profile is found for high luminosity and cool stars where the departures from LTE in the population of the n=2 level is expected to be the greatest. For a few stars, sample line profiles have been calculated in the LTE approximation to demonstrate the usefulness of the tabulated and displayed catalogue.