Investigating the Metallicity-Mixing Length Relation

التفاصيل البيبلوغرافية
العنوان: Investigating the Metallicity-Mixing Length Relation
المؤلفون: Viani, Lucas S., Basu, Sarbani, Ong, Joel J. M., Bonaca, Ana, Chaplin, William J.
سنة النشر: 2018
المجموعة: Astrophysics
مصطلحات موضوعية: Astrophysics - Solar and Stellar Astrophysics
الوصف: Stellar models typically use the mixing length approximation as a way to implement convection in a simplified manner. While conventionally the value of the mixing length parameter, $\alpha$, used is the solar calibrated value, many studies have shown that other values of $\alpha$ are needed to properly model stars. This uncertainty in the value of the mixing length parameter is a major source of error in stellar models and isochrones. Using asteroseismic data, we determine the value of the mixing length parameter required to properly model a set of about 450 stars ranging in $\log g$, $T_{\mathrm{eff}}$, and $\mathrm{[Fe/H]}$. The relationship between the value of $\alpha$ required and the properties of the star is then investigated. For Eddington atmosphere, non-diffusion models, we find that the value of $\alpha$ can be approximated by a linear model, in the form of $\alpha/\alpha_{\odot}=5.426 -0.101 \log (g) -1.071 \log (T_{\mathrm{eff}}) + 0.437 (\mathrm{[Fe/H]})$. This process is repeated using a variety of model physics as well as compared to previous studies and results from 3D convective simulations.
Comment: 20 pages, 17 figures, accepted for publication in ApJ
نوع الوثيقة: Working Paper
DOI: 10.3847/1538-4357/aab7eb
URL الوصول: http://arxiv.org/abs/1803.05924
رقم الأكسشن: edsarx.1803.05924
قاعدة البيانات: arXiv
الوصف
DOI:10.3847/1538-4357/aab7eb