反轨道潮汐碎屑的形成：土星Milky Way圆盘的起源
Making Counter-Orbiting Tidal Debris: The Origin of the Milky Way Disc of Satellites
摘要：
使用恒星动力学计算，它是第一次显示，反轨道物质自然出现在盘星系的潮汐相互作用。模型粒子在正反两个轨道上都可以在与质量比为1：1和4：1的盘星系的单次相遇中形成潮汐碎片。对于一系列不同的初始参数，共进行了74次模型计算。互动包括飞越和合并案例。产生的反轨道物质的比例在很大范围内变化（从几个百分比到50%）。所有飞越模型都显示出类似的两相行为，首先形成逆行物质。提取了逆行和逆行种群的属性，使观测判别成为可能。在这种遭遇过程中，潮汐碎片占据了相空间中的某个区域。在这种物质中，潮汐矮星系可能会形成。因此，模型可以解释为什么星系可能有矮星系轨道相反的大部分矮星系。一个例子是银河系的玉夫座矮星，它的轨道与卫星盘的大部分相反。因此，该模型支持的MW卫星的情况下，古老的潮汐矮星系形成的气态物质剥离从另一个星系在遇到年轻的MW。这个星系的一个可能候选者被确定为麦哲伦云的祖先星系。它的角运动与卫星物体MW圆盘的角运动相吻合。这种情况与林登-贝尔最初提出的dSph卫星的起源和LMC的近无约束轨道的建议一致。
英文摘要：
Using stellar-dynamical calculations it is shown for the first time that counter-orbiting material emerges naturally in tidal interactions of disc galaxies. Model particles on both pro- and retrograde orbits can be formed as tidal debris in single encounters with disc galaxies of 1-to-1 and 4-to-1 mass ratios. A total of 74 model calculations are performed for a range of different initial parameters. Interactions include fly-by and merger cases. The fraction of counter-orbiting material produced varies over a wide range (from a few up to 50 percent). All fly-by models show a similar two-phase behaviour, with retrograde material forming first. Properties of the prograde and retrograde populations are extracted to make an observational discrimination possible. During such encounters the tidal debris occupies a certain region in phase space. In this material, tidal-dwarf galaxies may form. The modelling therefore can explain why galaxies may have dwarf galaxies orbiting counter to the bulk of their dwarf galaxies. An example is the Sculptor dwarf of the Milky Way, which orbits counter to the bulk of the disc of satellites. The modelling thus supports the scenario of the MW satellites being ancient tidal-dwarf galaxies formed from gaseous material stripped from another galaxy during an encounter with the young MW. A possible candidate for this galaxy is identified as the Magellanic Cloud progenitor galaxy. Its angular motion fits the angular motion of the MW disc of satellites objects. This scenario is in agreement with Lynden-Bell's original suggestion for the origin of the dSph satellites and the near-unbound orbit of the LMC.
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。
