发表机构
National Central University; Curtin University; University of Texas, Austin（中央大学; 科廷大学; 德克萨斯大学奥斯汀分校）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过分析Trumpler 14星团中118个中等质量成员的盘和X射线特征，发现慢自转体与星周盘及X射线发射相关，提出高能过程可能是角动量损失的额外通道。
AI 中文摘要
中等质量（约1.5-8 M$_{\odot}$）恒星表现出广泛的旋转速率范围，并因其在一些年轻和中等年龄星团（年龄 $< 2$ Gyr）中观测到的扩展主序转折（eMSTO）中所起的作用而受到关注。尽管由于其辐射包层，预期这些恒星会快速旋转，但慢自转体的存在仍然令人困惑。在本研究中，我们检查了恒星形成星团Trumpler 14中中等质量成员的盘和X射线特征。在118个中等质量成员中，根据从光谱能量分布导出的红外光谱指数，24个被认为带有星周盘。这些成员中的大多数位于强辐照的星团核心之外，并且除了三个快速自转的Class III天体之外，其余均为慢自转体（$\lessapprox 100$ km s$^{-1}$）。此外，在同一118个样本中，37个是X射线源，其中22个具有可用的$v \sin i$数据，显示出比X射线宁静源系统性更慢的旋转。我们的研究结果表明，虽然中等质量恒星中的年轻星周盘有助于早期自转减速，但在此阶段由X射线发射示踪的高能过程可能是这些恒星角动量损失的额外通道。
英文摘要
Intermediate-mass (about 1.5-8 M$_{\odot}$) stars exhibit a wide range of rotation rates and have gained attention for their roles in the extended main-sequence turnoffs (eMSTO) seen in some young and intermediate-age clusters (ages $< 2$ Gyr). Although rapid rotation is expected due to their radiative envelopes, the presence of slow rotators remains puzzling. In this study, we examine disk and X-ray signatures among the intermediate-mass members of the star-forming cluster Trumpler 14. Of the 118 intermediate-mass members, 24 are considered disk-bearing on the basis of their infrared spectral indices derived from spectral energy distributions. The majority of these reside outside the heavily irradiated cluster core and are all slow rotators ($\lessapprox 100$ km s$^{-1}$) except for three fast-rotating Class III objects. Additionally, in the same sample of 118, 37 are X-ray sources, and 22 having available $v \sin i$ data show a systematically slower rotation than X-ray quiet sources. Our findings suggest that, while young stellar disks in intermediate-mass stars contribute to early spin-down, high-energy processes traced by X-ray emission during this phase could be an additional channel for angular-momentum loss in these stars.
CommentsAccepted for publication at ApJ
