Geometry of giant star model atmospheres: A consistency test

61Citations
Citations of this article
16Readers
Mendeley users who have this article in their library.

Abstract

Aims: We investigate the effect of a geometric inconsistency in the calculation of synthetic spectra of giant stars. Methods: Spectra computed with model atmospheres calculated in spherical geometry while using the plane-parallel approximation for line formation calculations (s_p), as well as the fully plane-parallel case (p_p), are compared to the consistently spherical case (s_s). Results: We present abundance differences for solar metallicity models with Teff ranging from 4000 to 6500 K and log g from 0.5 to 3.0 [cgs]. The effects are smaller for s_p calculations (-0.1 dex in the worst case) than for the p_p case (up to +0.35 dex for minority species and at most -0.04 dex for majority species), both with respect to the s_s case. In the s_p case the differences increase slightly with temperature, while in the p_p case they show a more complex behaviour. In both cases the effects decrease with increasing log g and increase with equivalent width. Conclusions: Within the parameter range of F, G and K giants, consistency seems to be less important than using a spherical model atmosphere. The abundance differences due to sphericity effects presented here can be used for error estimation in abundance studies relying on plane-parallel modelling. © ESO 2006.

Cite

CITATION STYLE

APA

Heiter, U., & Eriksson, K. (2006). Geometry of giant star model atmospheres: A consistency test. Astronomy and Astrophysics, 452(3), 1039–1048. https://doi.org/10.1051/0004-6361:20064925

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