期刊
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
卷 499, 期 2, 页码 2648-2661出版社
OXFORD UNIV PRESS
DOI: 10.1093/mnras/staa3028
关键词
methods: numerical; galaxies: formation; galaxies: kinematics and dynamics; galaxies: structure; dark matter; cosmology: theory
资金
- Gauss Centre for Supercomputing e.V.
- European Research Council under ERC-CoG grant [CRAGSMAN-646955]
- Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) [MO 2979/1-1]
We use cosmological hydrodynamical galaxy formation simulations from the NIHAO project to investigate the response of cold dark matter (CDM) haloes to baryonic processes. Previous work has shown that the halo response is primarily a function of the ratio between galaxy stellar mass and total virial mass, and the density threshold above which gas is eligible to form stars, n[cm(-3)]. At low n all simulations in the literature agree that dwarf galaxy haloes are cuspy, but at high n greater than or similar to 100 there is no consensus. We trace halo contraction in dwarf galaxies with n greater than or similar to 100 reported in some previous simulations to insufficient spatial resolution. Provided the adopted star formation threshold is appropriate for the resolution of the simulation, we show that the halo response is remarkably stable for n greater than or similar to 5, up to the highest star formation threshold that we test, n = 500. This free parameter can be calibrated using the observed clustering of young stars. Simulations with low thresholds n <= 1 predict clustering that is too weak, while simulations with high star formation thresholds n greater than or similar to 5, are consistent with the observed clustering. Finally, we test the CDM predictions against the circular velocities of nearby dwarf galaxies. Low thresholds predict velocities that are too high, while simulations with n greater than or similar to 10 provide a good match to the observations. We thus conclude that the CDM model provides a good description of the structure of galaxies on kpc scales provided the effects of baryons are properly captured.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据