We estimate the expected distribution of displacements between the dark matter (DM) and gas cores in simulated clusters. We use the MareNostrum Universe, one of the largest non-radiative, SPH ΛCDM cosmological simulations. We find that projected two-dimensional (2D) displacements between DM and gas, equal or larger than the observed in the Bullet Cluster, are expected in 1%-2% of the clusters with masses larger than 1014 h –1 M ☉. The 2D displacement distribution is roughly the same between redshifts 0 z 0.5 when multiplied by a factor of (1 + z)–1/2. We conclude that the separations between DM and gas as observed in the Bullet Cluster can easily be found in a ΛCDM universe. Furthermore, we find that the displacement distribution is not very sensitive to the normalization of the power spectrum. Upcoming surveys could extend the measurements of these displacements between DM and gas into large samples of hundreds of clusters, providing a potential test for ΛCDM.
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机译:我们估计模拟集群中暗物质(DM)和气核之间位移的预期分布。我们使用MareNostrum宇宙,这是最大的非辐射SPHΛCDM宇宙学模拟之一。我们发现,在质量大于1014 h –1 M the的团簇中,预期有1%-2%的DM与气体之间的二维(2D)位移等于或大于子弹团中的观测值。当乘以(1 + z)–1/2时,二维位移分布在0 展开▼