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Paper: Non-LTE Analysis of zYJ-band Spectra of Cepheids
Volume: 529, RR Lyrae/Cepheid 2019: Frontiers of Classical Pulsators
Page: 86
Authors: Przybilla, N.; Butler, K.; Ebenbichler, A.; Urbaneja, M. A.
Abstract: We study non-LTE effects on the spectral line-formation in Galactic Cepheids. The focus is on the short near-IR bands from 900 to 1350 nm. A hybrid non-LTE approach is chosen, based on standard LTE model atmospheres and subsequent non-LTE line-formation calculations. Neutral hydrogen, carbon, nitrogen, and oxygen are investigated, and the neutral/singly-ionized stages of magnesium. Overall, highly significant non-LTE effects are found, impacting both the outcome of the atmospheric parameter determination and elemental abundance analysis. The non-LTE strengthening of individual lines can give rise to abundance corrections of up to –0.7 dex.
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