论文标题
Lamost J040643.69+542347.8：银河系中最快的旋转器
LAMOST J040643.69+542347.8: the fastest Rotator in the Galaxy
论文作者
论文摘要
旋转和二元相互作用在理解巨大恒星的性质（> 8 msun）方面起着重要作用。一些有趣的瞬态，例如长持续的伽马射线爆发，被认为起源于快速旋转的巨星。由于强烈的恒星风能有效地旋转具有快速旋转的金属丰富的巨大恒星，因此很难在银河系中发现批判性旋转的单个巨星。在本报告中，在银河系中发现了最快的旋转器J040643.69+542347.8，其预计旋转速度vsini〜540 km/s的旋转速度〜540 km/s，比以前的记录持有人HD 191423的速度快〜100 km/s。它的4471吸收线是蓝光和不对称的，而其II 4686和HA的排放量具有中央吸收逆转。它也是一个失控的星星，这意味着在近距离二进制互动中的起源。与VFTS 285和VFTS 102（它们的Vsini〜610 km/s）相比，Lamost J040643.69+542347.8具有其自身的特殊光谱特性和较早的光谱类型。此外，Lamost J040643.69+542347.8是明亮的（B〜13.9 mag），足以允许将来的高分辨率光谱随访。
Rotation and binary interaction play important roles in understanding the nature of massive stars (>8 Msun). Some interesting transients, such as the long-duration gamma-ray bursts, are thought to be originated from fast-rotating massive stars. Because the strong stellar wind can effectively spin down a metal-rich massive star with fast rotation, it is very hard to find single massive stars rotating critically in the Galaxy. In the present work reported is the discovery of the fastest rotator in the Galaxy, LAMOST J040643.69+542347.8, with a projected rotational velocity vsini ~540 km/s, which is ~ 100 km/s faster than that of the previous record holder HD 191423. The star has a spectral type of O6.5 Vnnn(f)p. Its He I 4471 absorption line is blueshifted and asymmetric, while its He II 4686 and Ha have central absorption reversals in their emissions. It is also a runaway star, which implies an origin in a close binary interaction. Compared to VFTS 285 and VFTS 102 (their vsini ~ 610 km/s) in the Large Magellanic Cloud, LAMOST J040643.69+542347.8 has its own peculiar spectral characteristics and earlier spectral type. Moreover, LAMOST J040643.69+542347.8 is bright (B ~ 13.9 mag) enough to allow future high-resolution spectroscopic follow-ups.
