The impact of galactic feedback on the shapes of dark matter haloes
The impact of galactic feedback on the shapes of dark matter haloes
复制标题
星系反馈对暗物质晕形状的影响
DOI：
10.1093/mnras/stac1897
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发表时间：
2022
影响因子：
4.8
通讯作者：
Hernquist, Lars
中科院分区：
文献类型：
--
作者：
Chua, Kun Ting Eddie;Vogelsberger, Mark;Pillepich, Annalisa;Hernquist, Lars
我们使用 redshiftz= 0 的宇宙学模拟来量化星系形成对暗物质晕形状的影响。使用 IllustrisTNG 项目的磁流体动力学模拟，我们重点关注 50 Mpc (TNG50) 和 100 Mpc (TNG100) 盒子的质量晕，并将它们与仅暗物质 (DMO) 类似物和其他模拟进行比较，例如一百个天体物理物体的数值研究（NIHAO）和星系及其环境的演化和组装（EAGLE）。我们通过使用较小的 25 个盒子改变反馈模型来进一步量化预测不确定性。我们发现 (i) 与 DMO 模拟相比，星系形成导致更圆的光晕，与过去的结果在质量上一致。质量晕最呈球形，内晕的平均短轴与长轴比约为 0.75，与 DMO 对应物相比增加了 40%。对于低质量，不存在显着差异； (ii) 更强的反馈，例如增加银河风速，减少重子的影响； (iii) 内晕形状与恒星质量分数相关，解释了晕形状对反馈模型的依赖性； （iv）基准和较弱的反馈模型与银河系晕形状的观测估计最一致。在光晕质量固定的情况下，非常多样化且可能不切实际的反馈模型都预测内部形状彼此更接近，而不是 DMO 结果。由于晕与晕之间的晕形状差异很大，需要更大的观测样本来统计区分不同的重子处方。
We quantify the impact of galaxy formation on dark matter halo shapes using cosmological simulations at redshiftz= 0. Using magnetohydrodynamic simulations from the IllustrisTNG project, we focus on haloes of massfrom the 50 Mpc (TNG50) and 100 Mpc (TNG100) boxes and compare them to dark matter-only (DMO) analogues and other simulations, e.g. Numerical Investigation of a Hundred Astrophysical Objects (NIHAO) and Evolution and Assembly of GaLaxies and their Environments (EAGLE). We further quantify the prediction uncertainty by varying the feedback models using smaller 25boxes. We find that (i) galaxy formation results in rounder haloes compared to DMO simulations, in qualitative agreement with past results. Haloes of massare most spherical, with an average minor-to-major axial ratio of≈ 0.75 in the inner halo, an increase of 40 per cent compared to their DMO counterparts. No significant difference is present for low-masshaloes; (ii) stronger feedback, e.g. increasing galactic wind speed, reduces the impact of baryons; (iii) the inner halo shape correlates with the stellar mass fraction, explaining the dependence of halo shapes on feedback models; and (iv) the fiducial and weaker feedback models are most consistent with observational estimates of the Milky Way halo shape. At fixed halo mass, very diverse and possibly unrealistic feedback models all predict inner shapes closer to one another than to the DMO results. Because of the large halo-to-halo variation in halo shape, a larger observational sample is required to statistically distinguish different baryonic prescriptions.