The central densities of Milky Way-mass galaxies in cold and self-interacting dark matter models
The central densities of Milky Way-mass galaxies in cold and self-interacting dark matter models
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DOI：
10.1093/mnras/stab2173
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发表时间：
2021-02
影响因子：
4.8
通讯作者：
Omid Sameie;M. Boylan-Kolchin;R. Sanderson;Drona Vargya;P. Hopkins;A. Wetzel;J. Bullock;A. Graus;V. Robles
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作者：
Omid Sameie;M. Boylan-Kolchin;R. Sanderson;Drona Vargya;P. Hopkins;A. Wetzel;J. Bullock;A. Graus;V. Robles
我们提出了一套重子宇宙放大模拟的自相互作用暗物质（SIDM）晕内的“反馈在现实环境中”（FIRE）项目。这三个模拟的晕有维里质量$\sim 10^{12}\，\text{M}_\odot$在z = 0，我们研究速度无关的自相互作用截面为1和10 ${\rm cm ^2\，g^{-1}}$。我们研究了冷暗物质（CDM）和SIDM模型中的星星形成率和母晕的暗物质密度剖面形状。在z ≤ 1时，SIDM晕中形成的星系有更高的星星形成率，与CDM模拟相比，导致更多的大质量星系。虽然CDM和SIDM模拟都显示了不同形状的暗物质密度分布，但与CDM晕相比，SIDM晕可以在几个kpcs内达到更高和更陡峭的中心密度。我们确定了星系的半质量半径内的恒星的积累和中心暗物质密度的增长之间的相关性。在SIDM晕的热化过程中的一个致密的恒星组件的存在下，增强。因此，具有高度集中的重子轮廓的SIDM晕被预测为具有比CDM晕更高的中心暗物质密度。总的来说，SIDM晕比CDM晕更容易受到大量重子分布的影响。
We present a suite of baryonic cosmological zoom-in simulations of self-interacting dark matter (SIDM) haloes within the ‘Feedback In Realistic Environment’ (FIRE) project. The three simulated haloes have virial masses of $\sim 10^{12}\, \text{M}_\odot$ at z = 0, and we study velocity-independent self-interaction cross sections of 1 and 10 ${\rm cm^2 \, g^{-1}}$. We study star formation rates and the shape of dark matter density profiles of the parent haloes in both cold dark matter (CDM) and SIDM models. Galaxies formed in the SIDM haloes have higher star formation rates at z ≤ 1, resulting in more massive galaxies compared to the CDM simulations. While both CDM and SIDM simulations show diverse shape of the dark matter density profiles, the SIDM haloes can reach higher and more steep central densities within few kpcs compared to the CDM haloes. We identify a correlation between the build-up of the stars within the half-mass radii of the galaxies and the growth in the central dark matter densities. The thermalization process in the SIDM haloes is enhanced in the presence of a dense stellar component. Hence, SIDM haloes with highly concentrated baryonic profiles are predicted to have higher central dark matter densities than the CDM haloes. Overall, the SIDM haloes are more responsive to the presence of a massive baryonic distribution than their CDM counterparts.