Stellar Characterization and Radius Inflation of Hyades M-dwarf Stars from the APOGEE Survey-猫眼课题宝

DOI：

10.3847/1538-4357/acd4bd

发表时间：

2023-05

期刊：

The Astrophysical Journal

影响因子：

通讯作者：

中科院分区：

其他

文献类型：

作者：

Fábio Wanderley;K. Cunha;D. Souto;V. Smith;L. Cao;M. Pinsonneault;C. Allende Prieto;K. Covey;T. Masseron;I. Pascucci;K. Stassun;R. Terrien;Galen J. Bergsten;D. Bizyaev;Jos'e G. Fern'andez-Trincado;H. Jönsson;S. Hasselquist;J. Holtzman;R. Lane;S. Mahadevan;S. Majewski;D. Minniti;K. Pan;J. Serna;J. Sobeck;G. Stringfellow

利用斯隆数字巡天/阿帕奇点天文台银河演化实验（APOGEE）巡天的高分辨率H波段光谱，对毕宿星团48颗M矮星（0.2 M <$< M < 0.6 M <$）进行了光谱分析。我们的方法采用频谱合成与LTE MARCS模型大气，沿着与APOGEE数据发布17行列表，以确定有效温度，表面重力，金属丰度，和预计的旋转速度。毕宿星团M矮星的金属丰度中值为[M/H] = 0.09 ± 0.03 dex，表明内部不确定性很小，与毕宿星团红巨星的光学结果吻合得很好。总体而言，相对于MIST和达特茅斯等时线，中位半径分别比恒星模型预测的大1.6% ± 2.3%和2.4% ± 2.3%。然而，我们强调，这些等时线是不同的，完全和部分对流制度的分数半径膨胀有不同的行为取决于等时线。使用MIST等时线，完全对流的恒星没有半径膨胀的证据，而部分对流的M矮星的半径膨胀了2.7% ± 2.1%，这与包含磁场的模型的预测一致。对于部分对流恒星，快速旋转的恒星比缓慢旋转的恒星呈现出更高的膨胀水平。与SPOTS等时线模型的比较表明，导出的M矮星半径可以通过解释恒星光球层中的恒星斑点来解释，76%的研究M矮星的斑点覆盖率高达20%，最膨胀的恒星的斑点覆盖率为20%-40%。

We present a spectroscopic analysis of a sample of 48 M-dwarf stars (0.2 M ⊙ < M < 0.6 M ⊙) from the Hyades open cluster using high-resolution H-band spectra from the Sloan Digital Sky Survey/Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey. Our methodology adopts spectrum synthesis with LTE MARCS model atmospheres, along with the APOGEE Data Release 17 line list, to determine effective temperatures, surface gravities, metallicities, and projected rotational velocities. The median metallicity obtained for the Hyades M dwarfs is [M/H] = 0.09 ± 0.03 dex, indicating a small internal uncertainty and good agreement with optical results for Hyades red giants. Overall, the median radii are larger than predicted by stellar models by 1.6% ± 2.3% and 2.4% ± 2.3%, relative to a MIST and DARTMOUTH isochrone, respectively. We emphasize, however, that these isochrones are different, and the fractional radius inflation for the fully and partially convective regimes have distinct behaviors depending on the isochrone. Using a MIST isochrone there is no evidence of radius inflation for the fully convective stars, while for the partially convective M dwarfs the radii are inflated by 2.7% ± 2.1%, which is in agreement with predictions from models that include magnetic fields. For the partially convective stars, rapid rotators present on average higher inflation levels than slow rotators. The comparison with SPOTS isochrone models indicates that the derived M-dwarf radii can be explained by accounting for stellar spots in the photosphere of the stars, with 76% of the studied M dwarfs having up to 20% spot coverage, and the most inflated stars with ∼20%–40% spot coverage.

Stellar Characterization and Radius Inflation of Hyades M-dwarf Stars from the APOGEE Survey

文献摘要

相似文献