The light elements in the light of 3D and non-LTE effects - Astrophysics > Solar and Stellar AstrophysicsReport as inadecuate




The light elements in the light of 3D and non-LTE effects - Astrophysics > Solar and Stellar Astrophysics - Download this document for free, or read online. Document in PDF available to download.

Abstract: In this review we discuss possible systematic errors inherent in classical 1DLTE abundance analyses of late-type stars for the light elements here: H, He,Li, Be and B. The advent of realistic 3D hydrodynamical model atmospheres andthe availability of non-LTE line formation codes place the stellar analyses ona much firmer footing and indeed drastically modify the astrophysicalinterpretations in many cases, especially at low metallicities. For theTeff-sensitive hydrogen lines both stellar granulation and non-LTE are likelyimportant but the combination of the two has not yet been fully explored. Afortuitous near-cancellation of significant but opposite 3D and non-LTE effectsleaves the derived 7Li abundances largely unaffected but new atomic collisionaldata should be taken into account. We also discuss the impact on 3D non-LTEline formation on the estimated lithium isotopic abundances in halo stars inlight of recent claims that convective line asymmetries can mimic the presenceof 6Li. While Be only have relatively minor non-LTE abundance corrections, B issensitive even if the latest calculations imply smaller non-LTE effects thanpreviously thought.



Author: Martin Asplund, Karin Lind

Source: https://arxiv.org/







Related documents