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arXiv 1801.09682astro-ph.GA
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重子盘对自相互作用暗物质晕形状和轮廓的影响

The impact of baryonic discs on the shapes and profiles of self-interacting dark matter halos

Omid Sameie, Peter Creasey, Hai-Bo Yu, Laura V. Sales, Mark Vogelsberger, Jesus Zavala

摘要:

我们采用孤立N体模拟研究了自相互作用暗物质(SIDM)晕在重子势存在下的响应。暗物质的自相互作用导致内晕的运动热化,导致暗物质和重子分布之间的紧密相关。深重子势缩短了SIDM核心膨胀的阶段并触发核心收缩。这种效果可以通过大的自散射截面进一步增强。我们发现最终的SIDM密度分布对重子浓度和暗物质自相互作用的强度很敏感。假设初始晕为球形,我们还研究了SIDM晕形状的演化和密度分布。由于非球形盘势的影响,在以后的历元中,晕的形状偏离了球对称性,其意义取决于相对于暗物质的重子对总引力势的贡献。此外,我们构建了一个多分量模型的银河系,包括SIDM晕,恒星盘和隆起,并显示它是一致的观测恒星运动学和流。

英文摘要:

We employ isolated N-body simulations to study the response of self-interacting dark matter (SIDM) halos in the presence of the baryonic potentials. Dark matter self-interactions lead to kinematic thermalization in the inner halo, resulting in a tight correlation between the dark matter and baryon distributions. A deep baryonic potential shortens the phase of SIDM core expansion and triggers core contraction. This effect can be further enhanced by a large self-scattering cross section. We find the final SIDM density profile is sensitive to the baryonic concentration and the strength of dark matter self-interactions. Assuming a spherical initial halo, we also study evolution of the SIDM halo shape together with the density profile. The halo shape at later epochs deviates from spherical symmetry due to the influence of the non-spherical disc potential, and its significance depends on the baryonic contribution to the total gravitational potential, relative to the dark matter one. In addition, we construct a multi-component model for the Milky Way, including an SIDM halo, a stellar disc and a bulge, and show it is consistent with observations from stellar kinematics and streams.

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。

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