NLTE Analysis of Copper Lines in Different Stellar Populations ∗

  • Shi J
  • Yan H
  • Zhou Z
  • et al.
21Citations
Citations of this article
6Readers
Mendeley users who have this article in their library.

Abstract

The copper abundances of 29 metal-poor stars are determined based on the high-resolution, high-signal-to-noise ratio spectra from the UVES spectrograph at the ESO VLT telescope. Our sample consists of the stars of the Galactic halo, thick- and thin-disk, with [Fe/H] ranging from ∼−3.2 to ∼0.0 dex. The non-local thermodynamic equilibrium (NLTE) effects of Cu i lines are investigated, and line formation calculations are presented for an atomic model of copper including 97 terms and 1089 line transitions. We adopted the recently calculated photoionization cross sections of Cu i , and investigated the hydrogen collision by comparing the theoretical and observed line profiles of our sample stars. The copper abundances are derived for both local thermodynamic equilibrium (LTE) and NLTE based on the spectrum synthesis methods. Our results show that the NLTE effects for Cu i lines are important for metal-poor stars, in particular for very metal-poor stars, and these effects depend on the metallicity. For very metal-poor stars, the NLTE abundance correction reaches as large as ∼+0.5 dex compared to standard LTE calculations. Our results indicate that [Cu/Fe] is under-abundant for metal-poor stars (∼−0.5 dex) when the NLTE effects are included.

Cite

CITATION STYLE

APA

Shi, J. R., Yan, H. L., Zhou, Z. M., & Zhao, G. (2018). NLTE Analysis of Copper Lines in Different Stellar Populations ∗. The Astrophysical Journal, 862(1), 71. https://doi.org/10.3847/1538-4357/aacb22

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free