Iterative reconstruction excursions for Baryon Acoustic Oscillations and beyond
Iterative reconstruction excursions for Baryon Acoustic Oscillations and beyond
复制标题
重子声振荡及其他的迭代重建偏移
DOI：
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发表时间：
2021
影响因子：
4.8
通讯作者：
F. Beutler
中科院分区：
文献类型：
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作者：
H. Seo;A. Ota;M. Schmittfull;S. Saito;F. Beutler
密度场重建技术已被广泛用于恢复由于非线性而退化的星系探测中的重子声振荡(BAO)特征。最近的研究主张采用迭代步骤来提高回收率，远远超过标准技术。在本文中，我们研究了几种选定的迭代重建技术的性能，重点是BAO和宽带形状的两点聚类。我们考虑了红移空间的扭曲、晕偏和散粒噪声，并使用基于密度场的重建和基于位移场的重建，在傅立叶空间和位形空间中检查了重建场的分量。我们发现，在存在不可忽略的散粒噪声的情况下，位移场的重建很快就变得具有挑战性，因此我们提出了可以实际应用于更稀疏的场(如星系)的替代方法。对于银河场，实现去偏步骤以消除拉格朗日偏差似乎是位移场重建的关键。我们表明，迭代重建不会实质上改善BAO特征，而不是使用一个小的平滑核进行积极优化的标准重建。然而，我们发现，通过迭代步骤，我们可以更稳定地使用较小的平滑核，即不会在大范围内导致与线性功率谱的实质性偏差。在我们研究的一个具体例子中，我们发现，采用积极的标准重建的P(k∼0.1 h mpc−1)中13%的偏差可以通过迭代步骤减少到3%-4%。
The density field reconstruction technique has been widely used for recovering the Baryon Acoustic Oscillation (BAO) feature in galaxy surveys that has been degraded due to nonlinearities. Recent studies advocated adopting iterative steps to improve the recovery much beyond that of the standard technique. In this paper, we investigate the performance of a few selected iterative reconstruction techniques focusing on the BAO and the broadband-shape of the two-point clustering. We include redshift-space distortions, halo bias, and shot noise and inspect the components of the reconstructed field in Fourier space and in configuration space using both density field-based reconstruction and displacement field-based reconstruction. We find that the displacement field reconstruction becomes quickly challenging in the presence of non-negligible shot noise and therefore present surrogate methods that can be practically applied to a much more sparse field such as galaxies. For a galaxy field, implementing a debiasing step to remove the Lagrangian bias appears crucial for the displacement field reconstruction. We show that the iterative reconstruction does not substantially improve the BAO feature beyond an aggressively optimized standard reconstruction with a small smoothing kernel. However, we find taking iterative steps allows us to use a small smoothing kernel more ‘stably’, i.e. without causing a substantial deviation from the linear power spectrum on large scales. In one specific example we studied, we find that a deviation of 13 per cent in P(k ∼ 0.1 h Mpc−1) with an aggressive standard reconstruction can reduce to 3-4 per cent with iterative steps.