穿过星系晕的年轻恒星雨：Price-Whelan 1的性质和轨道
Young stars raining through the Galactic Halo: the nature and orbit of Price-Whelan 1
摘要：
我们给出了最近发现的年轻恒星系统Price-Whelan 1（PW 1）的五颗成员星的径向速度，该恒星系统位于遥远的星系晕（D~ 29 kpc，Z~ 15 kpc），可能与麦哲伦流的主导臂（LA）有关。我们测量了PW 1的径向速度，V_r=275 ± 10 km/s，明显大于LA气体的径向速度。根据这些新的观测结果，我们重新讨论了该系统的主要性质和起源，计算了该系统的轨道，并将其速度与HI在其周围的速度进行了比较。结果表明，在恒星速度下，大部分气体与PW 1的距离大于10 deg（5~kpc），气体与恒星之间的速度差随着气体离恒星的距离增大而增大.我们讨论的可能性是：（a）母气云溶解与银河系气体的相互作用，（b）母云是高速云HVC 287.5 +22.5+240，落后于恒星系统约25公里/秒和约10度。
英文摘要：
We present radial velocities for five member stars of the recently discovered young (age= 100-150 Myr) stellar system Price-Whelan 1 (PW 1), that is located far away in the Galactic Halo (D~ 29 kpc, Z~ 15 kpc), and that is probably associated to the Leading Arm (LA) of the Magellanic Stream. We measure the systemic radial velocity of PW 1, V_r=275 +/- 10 km/s, significantly larger than the velocity of the LA gas in the same direction. We re-discuss the main properties and the origin of this system in the light of these new observations, computing the orbit of the system and comparing its velocity with that of the HI in its surroundings. We show that the bulk of the gas at the velocity of the stars is more than 10 deg (5~kpc) away from PW 1 and the velocity difference between the gas and the stars become larger as gas closer to the stars is considered. We discuss the possibilities that (a) the parent gas cloud was dissolved by the interaction with the Galactic gas, and (b) that the parent cloud is the high velocity cloud HVC287.5+22.5+240, lagging behind the stellar system by ~25 km/s and ~10 deg.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
