论文标题
自相互作用的暗物质和超湿星系NGC1052-DF2和-DF4的起源
Self-Interacting Dark Matter and the Origin of Ultra-Diffuse Galaxies NGC1052-DF2 and -DF4
论文作者
论文摘要
对超扩散星系NGC 1052-DF2和-DF4的观察结果表明，它们可能包含很少的暗物质，从而挑战了我们对星系形成的理解。使用受控的N体模拟，我们探讨了它们的性质可以通过椭圆形的Galaxy NGC 1052，在冷暗物质（CDM）和自我相互作用的暗物质（SIDM）方案中复制的可能性。为了解释暗物质缺陷，我们发现CDM光环必须具有非常低的浓度，以便它在潮汐场中可能会失去足够的内部质量。相比之下，随着核心形成会增强潮汐质量损失，SIDM有利于更高，更合理的浓度。我们的SIDM基准中的最终恒星分布比CDM One更分散，因此前者与数据更加一致。我们进一步表明，通过强baryonic反馈修改的芯CDM晕模模型不太可能重现观测值。我们的结果表明，SIDM对形成深色缺陷星系的形成更有利。
Observations of ultra-diffuse galaxies NGC 1052-DF2 and -DF4 show they may contain little dark matter, challenging our understanding of galaxy formation. Using controlled N-body simulations, we explore the possibility that their properties can be reproduced through tidal stripping from the elliptical galaxy NGC 1052, in both cold dark matter (CDM) and self-interacting dark matter (SIDM) scenarios. To explain the dark matter deficiency, we find that a CDM halo must have a very low concentration so that it can lose sufficient inner mass in the tidal field. In contrast, SIDM favors a higher and more reasonable concentration as core formation enhances tidal mass loss. Final stellar distributions in our SIDM benchmarks are more diffuse than the CDM one, and hence the former are in better agreement with the data. We further show that a cored CDM halo model modified by strong baryonic feedback is unlikely to reproduce the observations. Our results indicate that SIDM is more favorable for the formation of dark-matter-deficient galaxies.
