文章基本信息

标题：Effective temperatures of red giants in the APOKASC catalogue and the mixing length calibration in stellar models
本地全文：下载
作者：M. Salaris ; S. Cassisi ; R. P. Schiavon 等
期刊名称：Astronomy & Astrophysics
印刷版ISSN：0004-6361
电子版ISSN：1432-0746
出版年度：2018
卷号：612
DOI：10.1051/0004-6361/201732340
语种：English
出版社：EDP Sciences
摘要：Red giants in the updated APOGEE-Keplercatalogue, with estimates of mass, chemical composition, surface gravity and effective temperature, have recently challenged stellar models computed under the standard assumption of solar calibrated mixing length. In this work, we critically reanalyse this sample of red giants, adopting our own stellar model calculations. Contrary to previous results, we find that the disagreement between theTeffscale of red giants and models with solar calibrated mixing length disappears when considering our models and the APOGEE-Keplerstars with scaled solar metal distribution. However, a discrepancy shows up whenα-enhanced stars are included in the sample. We have found that assuming mass, chemical composition and effective temperature scale of the APOGEE-Keplercatalogue, stellar models generally underpredict the change of temperature of red giants caused byα-element enhancements at fixed [Fe/H]. A second important conclusion is that the choice of the outer boundary conditions employed in model calculations is critical. Effective temperature differences (metallicity dependent) between models with solar calibrated mixing length and observations appear for some choices of the boundary conditions, but this is not a general result.
关键词：Key wordsenconvectionstars: low massstars: fundamental parameters