EXCITATION OF COUPLED STELLAR MOTIONS IN THE GALACTIC DISK BY ORBITING SATELLITES
EXCITATION OF COUPLED STELLAR MOTIONS IN THE GALACTIC DISK BY ORBITING SATELLITES
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DOI：
10.3847/0004-637x/823/1/4
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发表时间：
2015-11
期刊：
影响因子：
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通讯作者：
E. D’Onghia;P. Madau;C. Vera-Ciro;A. Quillen;L. Hernquist
中科院分区：
文献类型：
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作者：
E. D’Onghia;P. Madau;C. Vera-Ciro;A. Quillen;L. Hernquist
我们使用一组高分辨率的银河系盘N体模拟研究其与宇宙学预测的卫星人口的相互作用。一个模拟表明，具有不同速度的大质量卫星多次通过磁盘产生摆动，在恒星磁盘的正面投影中出现环。它们还在外盘部分产生耀斑，并通过弯曲波逐渐加热盘。一个不同的数值实验表明，一个像人马座矮星系一样大的卫星穿过圆盘，将驱动低密度区域中恒星的水平和垂直耦合振荡，伴随着小的相关加热。这个实验表明，在这些低密度区域的恒星的垂直偏移可以超过1千秒差距的太阳附近，类似于最近在当地检测到的相干垂直振荡。它们还可以引起10-20 km s−1的非零垂直流运动，这与最近在银盘中的观测结果一致。这种现象表现为局部环，伴有适度的盘加热。
We use a set of high-resolution N-body simulations of the Galactic disk to study its interactions with the population of cosmologically predicted satellites. One simulation illustrates that multiple passages of massive satellites with different velocities through the disk generate a wobble, which has the appearance of rings in face-on projections of the stellar disk. They also produce flares in the outer disk parts and gradually heat the disk through bending waves. A different numerical experiment shows that an individual satellite as massive as the Sagittarius dwarf galaxy passing through the disk will drive coupled horizontal and vertical oscillations of stars in underdense regions with small associated heating. This experiment shows that vertical excursions of stars in these low-density regions can exceed 1 kpc in the Solar neighborhood, resembling the recently locally detected coherent vertical oscillations. They can also induce non-zero vertical streaming motions as large as 10–20 km s−1, which is consistent with recent observations in the Galactic disk. This phenomenon appears as a local ring with modest associated disk heating.