重新审视Gaia DR3线宽的恒星赤道自转速度——温度、质量和年龄的依赖性
Revisiting Stellar equatorial rotational velocities with Gaia DR3 line broadening -- the dependence on temperature, mass and age
AI总结：
利用Gaia DR3数据研究恒星自转速度与温度、质量和年龄的关系，发现冷星自转减速较快，而热星在离开主序后才显著减速。
摘要：
我们利用超过10^5个Gaia DR3线宽vbroad测量值，研究恒星自转速度与温度、质量和年龄之间的关系。大规模样本清楚地显示了Kraft断点在约6500K，或质量约为1.3M⊙处，对于比断点更冷的恒星，vbroad较小，大约在10-20km/s之间，而在断点处，vbroad急剧上升，达到约100km/s，温度为7000K。为了跟踪恒星自转随年龄的变化，我们考虑vbroad作为缩放年龄（恒星年龄除以相关主序终期年龄）的函数，对于四个狭窄质量区间。我们发现，恒星自转减速在主序阶段较慢，而在恒星更热且离开主序后则更快，而对于较冷的恒星，减速率相对较高且变化不大。我们的发现与恒星自转减慢是由于磁性断裂的理论一致，这种断裂源于被锚定在恒星对流包层中的磁场。因此，冷星的减速较高，但热星只有在离开主序并形成对流外层后才出现减速。
英文摘要：
We used more than $10^5$ Gaia DR3 line broadening vbroad measurements to examine stellar rotation as a function of stellar temperature, mass and age. The large sample clearly displays the Kraft break at $\sim 6{,}500$\,K, or mass of $\sim1.3\,M_{\odot}$-while vbroad are small, on the order of $10$-$20$ km/s, for stars cooler than the Kraft break, they sharply rise above the break, reaching up $\sim100$ km/s with temperature of $7{,}000$ K. To follow the stellar rotation as a function of age, we consider vbroad as a function of scaled age-stellar age divided by the relevant Terminal Age Main Sequence (MS), for four narrow mass bins. We find that stellar rotation deceleration is slow during the MS phase and fast afterwards for stars hotter than the break, whereas deceleration rate is relatively high and does not vary much for the cool stars. Our findings are consistent with the theory that stellar rotation slowing is due to magnetic breaking, emanating from magnetic fields that are anchored to the stellar convective envelopes. Therefore, deceleration is high in cool stars, but in hot stars only after they leave the MS and develop convective outer layers
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