Internal rotation and buoyancy travel time of 60 gamma Doradus stars from uninterrupted TESS light curves spanning 352 days

Description:<br> Electronic versions of Table A.1 and A.2 from the Appendix of<br> Garcia et al. (2022b), as well as all analysed g-mode period-spacing<br> patterns from this work. Abstract:<br> Context. Gamma Doradus (hereafter gamma Dor) stars are gravity-mode<br> pulsators whose periods carry information about the internal structure of<br> the star. These periods are especially sensitive to the internal rotation<br> and chemical mixing, two processes that are currently not well constrained<br> in the theory of stellar evolution.<br> Aims. We aim to identify the pulsation modes and deduce the internal<br> rotation and buoyancy travel time for 106 gamma Dor stars observed<br> by the TESS mission in its southern continuous viewing zone (hereafter<br> S-CVZ). We rely on 140 previously detected period-spacing patterns, that is,<br> series of (near-)consecutive pulsation mode periods.<br> Methods. We used the asymptotic expression to compute gravity-mode<br> frequencies for ranges of the rotation rate and buoyancy travel time that<br> cover the physical range in γ Dor stars. Those frequencies were fitted to<br> the observed period-spacing patterns by minimizing a custom cost function.<br> The effects of rotation were evaluated using the traditional approximation<br> of rotation, using the stellar pulsation code GYRE.<br> Results. We obtained the pulsation mode identification, internal rotation<br> and buoyancy travel time for 60 TESS gamma Dor stars. For the remaining 46<br> targets, the detected patterns are either too short or contained too many<br> missing modes for unambiguous mode identification, and longer light curves<br> are required. For the successfully analysed stars, we found that<br> period-spacing patterns from 1-yr long TESS light curves can constrain the<br> internal rotation and buoyancy travel time to a precision of 0.03 d^{−1} and<br> 400s, respectively, which is about half as precise as literature results<br> based on 4-yr Kepler light curves of gamma Dor stars.数据集说明：本数据集包含Garcia等人（2022b）附录中表A.1与表A.2的电子版本，以及本研究中所有经分析的g模（g-mode）周期间距模式。 摘要： 研究背景：剑鱼座γ型星（Gamma Doradus，简称γ Dor）属于重力脉动变星，其脉动周期携带着恒星内部结构的相关信息。这类周期对内部自转与化学混合过程尤为敏感，而当前恒星演化理论中对这两个过程的约束仍较为薄弱。 研究目标：针对凌日系外行星巡天卫星（Transiting Exoplanet Survey Satellite，TESS）在南连续观测区（southern continuous viewing zone，简称S-CVZ）观测到的106颗γ Dor恒星，本研究旨在识别其脉动模式并推导出内部自转与浮力传播时间。我们依托140个此前已探测到的周期间距模式——即一系列（近似）连续的脉动模式周期序列。 研究方法：本研究采用渐近近似表达式，计算覆盖γ Dor恒星物理参数范围的自转速率与浮力传播时间区间内的重力模频率。通过最小化自定义代价函数，将计算得到的频率拟合至观测到的周期间距模式。我们借助恒星脉动代码GYRE，并采用传统旋转近似（traditional approximation of rotation）评估自转的影响。 研究结果：本研究成功为60颗TESS观测的γ Dor恒星完成了脉动模式识别，并推导出其内部自转与浮力传播时间。对于剩余46颗目标天体，要么探测到的模式序列过短，要么缺失过多模式，无法实现明确的模式识别，因此需要更长的测光光变曲线。针对成功完成分析的天体，我们发现：基于1年时长的TESS光变曲线得到的周期间距模式，可将内部自转与浮力传播时间的约束精度分别达到0.03 d⁻¹与400秒，这一精度约为基于4年开普勒（Kepler）望远镜γ Dor恒星光变曲线的文献结果的一半。