Imprints of relativistic effects on the asymmetry of the halo cross-correlation function: from linear to non-linear scales
Imprints of relativistic effects on the asymmetry of the halo cross-correlation function: from linear to non-linear scales
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DOI：
10.1093/mnras/sty3206
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发表时间：
2018-03
影响因子：
4.8
通讯作者：
Michel-Andrès Breton;Y. Rasera;A. Taruya;Osmin Lacombe;S. Saga
中科院分区：
文献类型：
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作者：
Michel-Andrès Breton;Y. Rasera;A. Taruya;Osmin Lacombe;S. Saga
通过从真实的空间到红移空间的映射（红移空间畸变，RSD），宇宙中大尺度结构的表观分布对源的速度/势以及沿视线的沿着势都很敏感。由于考虑标准多普勒RSD时晕互相关函数的奇多极子消失，偶极子是相对论和广角效应的灵敏探针。我们从一个新的“RayGalGroupSims”N体模拟的全天空光锥中建立了一个包含1000万个晕（银河系大小到星系团大小）的目录，该模拟覆盖了体积为（2.625 ~h^{-1}$Gpc）$^3$的4096^3 $粒子。使用射线跟踪技术，我们找到零测地线连接所有的源到观察者。然后，我们自洽地推导出所有的相对论贡献（在弱场近似）RSD：多普勒，横向多普勒，引力，透镜和综合萨克斯-沃尔夫。它允许我们，第一次，解开所有的贡献偶极子从线性到非线性尺度。在大尺度上，我们恢复的线性预测占主导地位的贡献，从附近的视线的分歧。虽然线性理论在非线性尺度下仍然是对偶极子速度贡献的合理近似，但它无法再现低于30 -60~h^{-1} Mpc的势能贡献（取决于晕质量）。在小于$\sim 10~h^{-1}$Mpc的尺度下，偶极主要是由引力红移引起的不对称性。这两种状态之间的转变也是质量依赖的。我们还确定了一个新的非平凡的贡献之间的非线性耦合的潜力和速度项。
The apparent distribution of large-scale structures in the universe is sensitive to the velocity/potential of the sources as well as the potential along the line-of-sight through the mapping from real space to redshift space (redshift-space distortions, RSD). Since odd multipoles of the halo cross-correlation function vanish when considering standard Doppler RSD, the dipole is a sensitive probe of relativistic and wide-angle effects. We build a catalogue of ten million haloes (Milky-Way size to galaxy-cluster size) from the full-sky light-cone of a new "RayGalGroupSims" N-body simulation which covers a volume of ($2.625~h^{-1}$Gpc)$^3$ with $4096^3$ particles. Using ray-tracing techniques, we find the null geodesics connecting all the sources to the observer. We then self-consistently derive all the relativistic contributions (in the weak-field approximation) to RSD: Doppler, transverse Doppler, gravitational, lensing and integrated Sachs-Wolfe. It allows us, for the first time, to disentangle all contributions to the dipole from linear to non-linear scales. At large scale, we recover the linear predictions dominated by a contribution from the divergence of neighbouring line-of-sights. While the linear theory remains a reasonable approximation of the velocity contribution to the dipole at non-linear scales it fails to reproduce the potential contribution below $30-60~h^{-1}$Mpc (depending on the halo mass). At scales smaller than $\sim 10~h^{-1}$Mpc, the dipole is dominated by the asymmetry caused by the gravitational redshift. The transition between the two regimes is mass dependent as well. We also identify a new non-trivial contribution from the non-linear coupling between potential and velocity terms.