NGTS clusters survey - V. Rotation in the Orion star-forming complex
NGTS clusters survey - V. Rotation in the Orion star-forming complex
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NGTS 星团巡天 - V. 猎户座恒星形成复合体中的旋转
DOI：
10.1093/mnras/stad1435
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发表时间：
2023
影响因子：
4.8
通讯作者：
Smith G
中科院分区：
文献类型：
--
作者：
Smith G
我们提出了一个旋转30平方度的猎户座恒星形成复合体的研究，下一代过境调查（NGTS）的200天光度监测活动。从5749猎户座成员的光变曲线，我们报告了2268个对象的周期性签名和分析旋转周期分布作为一个函数的颜色为1789颗恒星的光谱类型F0-M5。我们选择候选成员的猎户座usingGaibrance和分配我们的目标，运动子群。我们校正星际灭绝的恒星由星星的基础上，并确定恒星和星团的年龄使用磁性和非磁性恒星演化模型。自转周期一般在1-10 d之间，只有1.5%的经典金牛座T星或I/II类年轻恒星天体的自转周期短于1.8 d，而弱线金牛座T星或III类天体的自转周期短于1.8 d的占14%。在周期色空间中，与1- 300万年的恒星相比，3- 600万年的低质量（>M2）恒星的自转周期分布向更短的周期移动，晚于M3.5的恒星的自转周期不超过10 d。这可能反映了星周盘扩散的质量依赖性。最后，我们认为，营业额（从增加到减少的时期）的周期颜色分布可能会发生在较低的质量为老年人口：在1- 300万年的光谱类型的10 K5转移到10 M1在3- 600万年。
We present a study of rotation across 30 square degrees of the Orion Star-forming Complex, following a ∼200 d photometric monitoring campaign by the Next Generation Transit Survey (NGTS). From 5749 light curves of Orion members, we report periodic signatures for 2268 objects and analyse rotation period distributions as a function of colour for 1789 stars with spectral types F0–M5. We select candidate members of Orion usingGaiadata and assign our targets to kinematic sub-groups. We correct for interstellar extinction on a star-by-star basis and determine stellar and cluster ages using magnetic and non-magnetic stellar evolutionary models. Rotation periods generally lie in the range 1–10 d, with only 1.5 per cent of classical T Tauri stars or Class I/II young stellar objects rotating with periods shorter than 1.8 d, compared with 14 per cent of weak-line T Tauri stars or Class III objects. In period–colour space, the rotation period distribution moves towards shorter periods among low-mass (>M2) stars of age 3–6 Myr, compared with those at 1–3 Myr, with no periods longer than 10 d for stars later than M3.5. This could reflect a mass-dependence for the dispersal of circumstellar discs. Finally, we suggest that the turnover (from increasing to decreasing periods) in the period–colour distributions may occur at lower mass for the older-aged population: ∼K5 spectral type at 1–3 Myr shifting to ∼M1 at 3–6 Myr.