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arXiv 0901.3085astro-ph.CO
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重子声学峰的定位

Locating the Baryon Acoustic Peak

Fergus Simpson, John A. Peacock, Patrick Simon

摘要:

即将到来的测光红移调查应提供一个准确的探头的声学峰值在两点星系关联函数,在一个给定的壳层内的星系角集群的形式在红移空间。我们调查的形式的预期信号,量化的失真,由于投影效应,特别是探索应用Limber近似的有效性。一个单一的积分处方,它提供了一种替代林伯的方程,并产生显着改善的预测在该制度的利益。在角度关联函数内的声峰的位置与到红移仓的远侧的角直径距离有关。因此,较厚的红移仓使同向运动特征向较小的角尺度移动。因此,测光红移误差的值获得了更大的意义,特别是在较低的红移。为了将暗能量状态方程恢复到1%的水平,我们发现总红移色散必须确定在Δσ_z ~ 10^-3之内,这在实践中可能证明是具有挑战性的。

英文摘要:

Forthcoming photometric redshift surveys should provide an accurate probe of the acoustic peak in the two-point galaxy correlation function, in the form of angular clustering of galaxies within a given shell in redshift space. We investigate the form of the anticipated signal, quantifying the distortions that arise due to projection effects, and in particular explore the validity of applying the Limber approximation. A single-integral prescription is presented, which provides an alternative to Limber's equation, and produces a significantly improved prediction in the regime of interest. The position of the acoustic peak within the angular correlation function relates to the angular diameter distance to the far side of the redshift bin. Thicker redshift bins therefore shift comoving features towards smaller angular scales. As a result, the value of the photometric redshift error acquires a greater significance, particularly at lower redshifts. In order to recover the dark energy equation of state to a level of 1%, we find the total redshift dispersion must be determined to within Δσ_z ~ 10^-3, which may prove challenging to achieve in practice.

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