Tidal stripping as a possible origin of the ultra diffuse galaxy lacking dark matter
Tidal stripping as a possible origin of the ultra diffuse galaxy lacking dark matter
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DOI：
10.1093/mnrasl/sly138
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发表时间：
2018-10-01
影响因子：
4.8
通讯作者：
Ogiya, Go
中科院分区：
文献类型：
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作者：
Ogiya, Go
最近的观测揭示了一个神秘的超扩散星系 NGC 1052-DF2，它位于一个大型椭圆星系 NGC 1052 的群中。与丰度匹配模型的预期相比，NGC 1052-DF2 中包含的暗物质质量小了大约 400 倍。我们利用受控 N 体模拟 NGC 1052 和一个较小的卫星星系（我们认为该卫星星系是 NGC 的前身）之间的潮汐相互作用。 1052-DF2，测试潮汐剥离是否可以解释这种水平的暗物质缺乏。我们发现，当假设卫星暗晕有紧密束缚且相当径向的轨道和核心密度结构时，我们的模拟很好地再现了从 NGC 1052-DF2 观测推断出的质量分布和有效半径。轨道参数位于尾部，但仍然与宇宙学模拟对其分布的测量结果一致。因此，在我们的假设中，这种强烈缺乏暗物质的星系预计在星系团和星团中相对罕见，并且不存在于现场。
Recent observations revealed a mysterious ultra diffuse galaxy, NGC 1052-DF2, in the group of a large elliptical galaxy, NGC 1052. Compared to expectations from abundance matching models, the dark matter mass contained in NGC 1052-DF2 is smaller by a factor of similar to 400. We utilize controlled N-body simulations of the tidal interaction between NGC 1052 and a smaller satellite galaxy that we suppose as the progenitor of NGC 1052-DF2, to test if tidal stripping can explain dark-matter deficiency at such levels. We find that when assuming a tightly bound and quite radial orbit and cored density structure for the dark halo of the satellite, our simulations reproduce well both the mass profile and the effective radius inferred from the observations of NGC 1052-DF2. Orbital parameters are in the tail, but still consistent with measurements of their distributions from cosmological simulations. Such strongly dark-matter deficient galaxies, in our scenario, are thus expected to be relatively rare in groups and clusters, and not present in the field.