论文标题
AGB恒星中的磁性诱导诱导混合：前置SIC晶粒
Magnetic-buoyancy Induced Mixing in AGB Stars: Presolar SiC Grains
论文作者
论文摘要
同位素比在渗透级（0.1 \％）精度的古代渐近巨型分支（AGB）恒星中测量的同位素比。与传统的光谱观测相比，这种精确的谷物数据允许在AGB模型中对混合效率进行更严格的约束和校准。在本文中，我们将SIC重元同位素比与一系列新的果味模型进行了比较，其中包括由磁场触发的混合的效果。基于文献中可用的2D和3D仿真，我们提出了一种新的公式，可以在其上得出由磁场引起的混合的一般特征。另一方面，这种混合的效率依赖于物理量的限制很差。我们在这里通过将模型结果与来自AGB恒星的Presolar SiC晶粒的重元素同位素数据进行比较，在这里介绍了我们的校准。我们证明，可以通过在我们的新果味模型中采用单个磁场构型来同时拟合所有测量元素（Ni，Sr，Zr，Mo，Ba）的同位素组合物（Ni，Sr，Zr，Mo，Ba）。
Isotope ratios can be measured in presolar SiC grains from ancient Asymptotic Giant Branch (AGB) stars at permil-level (0.1\%) precision. Such precise grain data permit derivation of more stringent constraints and calibrations on mixing efficiency in AGB models than traditional spectroscopic observations. In this paper we compare SiC heavy-element isotope ratios to a new series of FRUITY models that include the effects of mixing triggered by magnetic fields. Based on 2D and 3D simulations available in the literature, we propose a new formulation, upon which the general features of mixing induced by magnetic fields can be derived. The efficiency of such a mixing, on the other hand, relies on physical quantities whose values are poorly constrained. We present here our calibration by comparing our model results with the heavy-element isotope data of presolar SiC grains from AGB stars. We demonstrate that the isotopic compositions of all measured elements (Ni, Sr, Zr, Mo, Ba) can be simultaneously fitted by adopting a single magnetic field configuration in our new FRUITY models.
