Galaxies lacking dark matter produced by close encounters in a cosmological simulation
Galaxies lacking dark matter produced by close encounters in a cosmological simulation
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DOI：
10.1038/s41550-021-01598-4
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发表时间：
2022-02-14
期刊：
影响因子：
14.1
通讯作者：
Keres, Dusan
中科院分区：
文献类型：
--
作者：
Moreno, Jorge;Danieli, Shany;Keres, Dusan
标准的冷暗物质加宇宙学常数模型预测星系形成于暗物质晕中，并且低质量星系比大质量星系更受暗物质支配。两个缺乏暗物质的低质量星系的意外发现立即引发了对标准宇宙学的担忧，并引发了对替代方案的探索，包括自相互作用的暗物质和修正的引力。Approximation增长后，几个宇宙学模拟使用传统的模型未能形成足够的数值模拟与可比的内部特征（恒星质量，大小，速度色散和形态）。在这里，我们表明，标准的范式自然产生的星系缺乏暗物质的内部特征与观测一致。使用最先进的宇宙学模拟和细致的星系识别技术，我们发现与大质量邻居的极端近距离接触可能是造成这一点的原因。我们预测，大约30%的大质量中央星系（恒星质量至少为10（11）个太阳）至少有一个暗物质缺乏的卫星（恒星质量为10（8）-10（9）个太阳）。这类独特的星系为我们理解相互作用在塑造星系特性中的作用提供了额外的一层。未来对上述星系的观测将对这一设想进行重要的检验。
The standard cold dark matter plus cosmological constant model predicts that galaxies form within dark-matter haloes, and that low-mass galaxies are more dark-matter dominated than massive ones. The unexpected discovery of two low-mass galaxies lacking dark matter immediately provoked concerns about the standard cosmology and ignited explorations of alternatives, including self-interacting dark matter and modified gravity. Apprehension grew after several cosmological simulations using the conventional model failed to form adequate numerical analogues with comparable internal characteristics (stellar masses, sizes, velocity dispersions and morphologies). Here we show that the standard paradigm naturally produces galaxies lacking dark matter with internal characteristics in agreement with observations. Using a state-of-the-art cosmological simulation and a meticulous galaxy-identification technique, we find that extreme close encounters with massive neighbours can be responsible for this. We predict that similar to 30% of massive central galaxies (with at least 10(11) solar masses in stars) harbour at least one dark-matter-deficient satellite (with 10(8)-10(9) solar masses in stars). This distinctive class of galaxies provides an additional layer in our understanding of the role of interactions in shaping galactic properties. Future observations surveying galaxies in the aforementioned regime will provide a crucial test of this scenario.