The effects of surface fossil magnetic fields on massive star evolution: IV. Grids of models at Solar, LMC, and SMC metallicities
The effects of surface fossil magnetic fields on massive star evolution: IV. Grids of models at Solar, LMC, and SMC metallicities
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表面化石磁场对大质量恒星演化的影响：IV。
DOI：
10.1093/mnras/stac2598
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发表时间：
2022
影响因子：
4.8
通讯作者：
Keszthelyi Z
中科院分区：
文献类型：
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作者：
Keszthelyi Z
磁场可以通过质量损失淬火，磁制动和有效的角动量传输来彻底改变大质量恒星演化模型的预测，我们的目标是在这项工作中量化。我们使用themesasoftware仪器来计算恒星结构和演化模型的广泛的主序星网格，以及等时线，解释归因于表面化石磁场的影响。网格的初始质量（3-60 M）、表面赤道磁场强度（0-50 kG）和金属丰度（代表太阳邻域和麦哲伦云）都很密集。我们使用两个磁制动和两个化学混合方案，并比较模型的预测缓慢旋转，富氮（“2组”）的大麦哲伦星云的观测恒星。我们量化了一系列的初始场强，允许生产组2星，并发现典型的值（高达几公斤）导致的解决方案。在子网格之间，我们发现表面丰度和演化路径有显着的偏离。在我们的磁性模型中，由于快速自旋下降，与非磁性模型相比，化学混合总是效率较低。我们确定，准化学均匀的主序列演化的有效混合可以防止化石磁场。我们建议将这个演化模型网格与分光偏振和光谱观测进行比较，目的是（i）重新审视已知磁星的恒星参数，（ii）在观测上限制不确定的磁制动和化学混合方案。
Magnetic fields can drastically change predictions of evolutionary models of massive stars via mass-loss quenching, magnetic braking, and efficient angular momentum transport, which we aim to quantify in this work. We use themesasoftware instrument to compute an extensive main-sequence grid of stellar structure and evolution models, as well as isochrones, accounting for the effects attributed to a surface fossil magnetic field. The grid is densely populated in initial mass (3–60 M⊙), surface equatorial magnetic field strength (0–50 kG), and metallicity (representative of the Solar neighbourhood and the Magellanic Clouds). We use two magnetic braking and two chemical mixing schemes and compare the model predictions for slowly rotating, nitrogen-enriched (‘Group 2’) stars with observations in the Large Magellanic Cloud. We quantify a range of initial field strengths that allow for producing Group 2 stars and find that typical values (up to a few kG) lead to solutions. Between the subgrids, we find notable departures in surface abundances and evolutionary paths. In our magnetic models, chemical mixing is always less efficient compared to non-magnetic models due to the rapid spin-down. We identify that quasi-chemically homogeneous main sequence evolution by efficient mixing could be prevented by fossil magnetic fields. We recommend comparing this grid of evolutionary models with spectropolarimetric and spectroscopic observations with the goals of (i) revisiting the derived stellar parameters of known magnetic stars, and (ii) observationally constraining the uncertain magnetic braking and chemical mixing schemes.
ap星的磁场与太阳型恒星的磁场之间的边界
影响因子：
6.9
作者：
J. Landstreet
通讯作者：
J. Landstreet