A non-LTE study of neutral and singly-ionized calcium in late-type stars

2006/09/19 by L. Mashonkina, A. J. Korn, N. Przybilla · 202 citations
Chemistry · Mathematics · Physics and Astronomy · #Abundance (ecology) #Astro and Planetary Science #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Biology #Calcium #Chemistry #Ion #Ionization #Line (geometry) #Mathematics #Metal #Physics #Spectral line #Stars #Stellar, planetary, and galactic studies #Surface gravity #Thermodynamic equilibrium #Thermodynamics #astro-ph

paper · pdf · doi:10.1051/0004-6361:20065999

published in Astronomy and Astrophysics 461(1), 261-275 (EDP Sciences) · 17 pages, accepted for publication in A&A

arxiv created 2006/09/19 · openalex publication_date 2006/10/04 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

Aims.Non-local thermodynamical equilibrium (NLTE) line formation for neutral and singly-ionized calcium is considered through a range of spectral types when the Ca abundance varies from the solar value down to [Ca/H] = -5. We evaluate the influence of departures from LTE on Ca abundance determinations and inspect the possibility of using / line-strength ratios as indicators of surface gravity for extremely metal-poor stars.

Citations

• The Impact of Non‐LTE Effects and Granulation Inhomogeneities on the Derived Iron and Oxygen Abundances in Metal‐Poor Halo Stars
• Using the Ca II triplet to trace abundance variations in individual red giant branch stars in three nearby galaxies
• Physical properties of solar chromospheric plages
• Nucleosynthetic signatures of the first stars

Cited by

• The NIR Ca ii triplet at low metallicity
• The Na-O anticorrelation in horizontal branch stars
• The elemental composition of the Sun
• The formation of the Milky Way halo and its dwarf satellites: A NLTE–1D abundance analysis. V. The Sextans galaxy
• Non-LTE line formation for heavy elements in four very metal-poor stars
• A NLTE line formation for neutral and singly ionized calcium in model atmospheres of B-F stars
• GaiaFGK benchmark stars: Effective temperatures and surface gravities
• Atomic diffusion and mixing in old stars
• Influence of departures from LTE on calcium, titanium, and iron abundance determinations in cool giants of different metallicities
• Statistical equilibrium of silicon in the atmospheres of metal-poor stars