The peculiar velocity field up to z ∼ 0.05 by forward-modelling Cosmicflows-3 data
The peculiar velocity field up to z ∼ 0.05 by forward-modelling Cosmicflows-3 data
复制标题
通过对 Cosmicflows-3 数据进行正演建模，得到高达 z 〜 0.05 的奇特速度场
DOI：
10.1093/mnras/stz078
复制
发表时间：
2019
影响因子：
4.8
通讯作者：
Daniel Pomarède
中科院分区：
文献类型：
--
作者：
R. Graziani;H. Courtois;G. Lavaux;Y. Hoffman;R. Tully;Y. Copin;Daniel Pomarède
一个分层贝叶斯模型应用于宇宙流-3目录的星系距离，以获得特殊的速度场和分布的物质在z <$0.054。该模型假设线性区域内的ΛCDM模型，并包括星系距离与底层密度场的拟合。通过对数据进行正演模拟，该方法能够减轻特殊速度分析所固有的偏差，例如齐次Malmquist偏差或特殊速度的对数正态分布。恢复的速度场的统计不确定性约为150 km s−1，取决于位置，我们研究了来自选择函数和距离指标校准的系统学。由此产生的速度场和相关的密度场恢复了本地宇宙的宇宙学，这是我们宇宙前所未有的体积，比以前达到的大10倍。这种方法打开了大门，重建初始条件更大，更准确的约束宇宙学模拟。这项工作也是准备更大的奇特的速度数据集来自Wallaby，TAIPAN，或LSST。
A hierarchical Bayesian model is applied to the Cosmicflows-3 catalogue of galaxy distances in order to derive the peculiar velocity field and distribution of matter within z ∼ 0.054. The model assumes the ΛCDM model within the linear regime and includes the fit of the galaxy distances together with the underlying density field. By forward modelling the data, the method is able to mitigate biases inherent to peculiar velocity analyses, such as the Homogeneous Malmquist bias or the lognormal distribution of peculiar velocities. The statistical uncertainty on the recovered velocity field is about 150 km s−1 depending on the location, and we study systematics coming from the selection function and calibration of distance indicators. The resulting velocity field and related density fields recover the cosmography of the Local Universe which is presented in an unprecedented volume of our Universe 10 times larger than previously reached. This methodology opens the doors to reconstruction of initial conditions for larger and more accurate constrained cosmological simulations. This work is also preparatory to larger peculiar velocity data sets coming from Wallaby, TAIPAN, or LSST.