Logo
ScienceStack
Table of Contents
Fetching ...
Sign In

ExoAtom: A Database of Atomic Spectra in ExoMol Format

Qing-He Ni, Rujia Wang, Tianyang Xie, Jingxin Zhang, Christian Hill, Sergei N. Yurchenko, Jonathan Tennyson

TL;DR

This paper introduces ExoAtom, a new ExoMol-format database of atomic line lists derived from the NIST and Kurucz databases for neutral atoms and singly ionized species. Data are structured as the ExoMol file types .all, .def, .states, .trans, and .pf, with transitions carrying Einstein $A_{ki}$ coefficients and transition wavenumbers $ ilde{v}_{if}$ and partition functions $Q(T)$ across a temperature grid, enabling post-processing with PyExoCross. NIST provides high-accuracy experimental data while Kurucz supplies broader completeness; partition functions are obtained via direct summation in NIST and via precomputed curves in Kurucz, and a master file exoatom.all.json consolidates 151 atomic species with isotope entries. Applications include modeling stellar and exoplanetary atmospheres, with comparisons showing NIST and Kurucz agreement in key features at 3000–6000 K and a roadmap to add more ionization stages and line-broadening parameters.

Abstract

We present the ExoAtom database, www.exomol.com/exoatom, an extension of the ExoMol database to provide atomic line lists in the ExoMol format. ExoAtom is designed for detailed astrophysical, planetary, and laboratory applications. ExoAtom currently includes atomic data for 80 neutral atoms and 74 singly charged ions. These data are extracted from both the NIST and Kurucz databases, with 79/71 atoms/ions sourced from NIST and 38/37 atoms/ions sourced from Kurucz. ExoAtom uses the file types .all, .def, .states, .trans and .pf as fundamental components for structuring atomic data in a consistent hierarchy. The .states file contains quantum numbers, uncertainties, lifetimes, etc. The .trans file specifies Einstein A coefficients and their associated wavenumbers. The .pf file provides partition functions over a wide grid of temperatures. Post-processing of the ExoAtom data is provided by the program PyExoCross. Future development of ExoAtom will include additional ionization stages.

ExoAtom: A Database of Atomic Spectra in ExoMol Format

TL;DR

This paper introduces ExoAtom, a new ExoMol-format database of atomic line lists derived from the NIST and Kurucz databases for neutral atoms and singly ionized species. Data are structured as the ExoMol file types .all, .def, .states, .trans, and .pf, with transitions carrying Einstein coefficients and transition wavenumbers and partition functions across a temperature grid, enabling post-processing with PyExoCross. NIST provides high-accuracy experimental data while Kurucz supplies broader completeness; partition functions are obtained via direct summation in NIST and via precomputed curves in Kurucz, and a master file exoatom.all.json consolidates 151 atomic species with isotope entries. Applications include modeling stellar and exoplanetary atmospheres, with comparisons showing NIST and Kurucz agreement in key features at 3000–6000 K and a roadmap to add more ionization stages and line-broadening parameters.

Abstract

We present the ExoAtom database, www.exomol.com/exoatom, an extension of the ExoMol database to provide atomic line lists in the ExoMol format. ExoAtom is designed for detailed astrophysical, planetary, and laboratory applications. ExoAtom currently includes atomic data for 80 neutral atoms and 74 singly charged ions. These data are extracted from both the NIST and Kurucz databases, with 79/71 atoms/ions sourced from NIST and 38/37 atoms/ions sourced from Kurucz. ExoAtom uses the file types .all, .def, .states, .trans and .pf as fundamental components for structuring atomic data in a consistent hierarchy. The .states file contains quantum numbers, uncertainties, lifetimes, etc. The .trans file specifies Einstein A coefficients and their associated wavenumbers. The .pf file provides partition functions over a wide grid of temperatures. Post-processing of the ExoAtom data is provided by the program PyExoCross. Future development of ExoAtom will include additional ionization stages.
Paper Structure (18 sections, 2 equations, 2 figures, 20 tables)

This paper contains 18 sections, 2 equations, 2 figures, 20 tables.

Table of Contents

  1. Introduction
  2. Data Coverage
  3. Database Structure
  4. ExoMol Format
  5. NIST Databases
  6. Kurucz Databases
  7. File Naming Convention
  8. Data Format
  9. The Definition File
  10. The Master File
  11. States Files
  12. Trans Files
  13. Partition functions
  14. Post Processing
  15. Conclusions
  16. ...and 3 more sections

Figures (2)

  • Figure 1: Comparison of partition functions for Al I, Fe I and Mg I, see text for further details.
  • Figure 2: Comparison of NISTralchenko2020development and Kurucz Kurucz2017 Fe I emission spectra at 3000 K and 6000 K; the 6000 K spectrum contains many lines only present in the Kurucz dataset.