论文标题
M101 / NGC 5474的动态模型
A Dynamical Model of the M101 / NGC 5474 Encounter
论文作者
论文摘要
我们提出了第一个动态模拟，该模拟重新创建了附近螺旋星系M101的主要特性。我们的模型描述了伴侣Galaxy NGC 5474通过M101的外磁盘的放牧但相对较近（14 kpc）的段落，大约200 Myr。这两个磁盘都是逆行的，该磁盘会产生相对较强的重力响应，同时抑制长潮汐尾巴的形成。该模拟再现了M101的整体偏斜性，以及银河系磁盘的延伸的NE羽状和锋利的西部边缘。在M101的NE羽流中观察到的恒星后种群可能是由于星系碰撞的接触点触发的恒星形成的结果。随着时间的流逝，该材料将方位角混合，在M101的外磁盘中留下弥漫性，运动学连贯的恒星流。在相遇后的后期，M101的磁盘的密度曲线显示出与较密集环境中螺旋星系相似的“上升”曲线，进一步证明了星系磁盘的相互作用与长期结构变化之间的联系。
We present the first dynamical simulation that recreates the major properties of the archetypal nearby spiral galaxy M101. Our model describes a grazing but relatively close (14 kpc) passage of the companion galaxy NGC 5474 through M101's outer disk approximately 200 Myr ago. The passage is retrograde for both disks, which yields a relatively strong gravitational response while suppressing the formation of long tidal tails. The simulation reproduces M101's overall lopsidedness, as well as the extended NE Plume and sharp western edge of the galaxy's disk. The post-starburst populations observed in M101's NE Plume are likely a result of star formation triggered at the point of contact where the galaxies collided. Over time, this material will mix azimuthally, leaving behind diffuse, kinematically coherent stellar streams in M101's outer disk. At late times after the encounter, the density profile of M101's disk shows a broken "upbending" profile similar to those seen in spiral galaxies in denser environments, further demonstrating the connection between interactions and long-term structural changes in galaxy disks.
