Mitigating the impact of fiber assignment on the measurement of galaxy-lensing cross correlation
Mitigating the impact of fiber assignment on the measurement of galaxy-lensing cross correlation
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DOI：
10.1088/1475-7516/2022/03/008
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发表时间：
2021-10
影响因子：
6.4
通讯作者：
R. Makiya;Tomomi Sunayama
中科院分区：
文献类型：
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作者：
R. Makiya;Tomomi Sunayama
我们研究了光纤分配对星系团测量的影响及其与弱透镜场的相互关系。与重子振荡光谱巡天（BOSS）等以往的星系巡天不同，目前正在进行的星系巡天，如定焦光谱仪（PFS）和暗能量光谱仪（DESI），由于目标星系比可用的光纤多，受到光纤分配的影响更为严重。以往的研究发现，光纤分配抑制了星系功率谱在所有尺度上的振幅。我们新发现光纤分配引入了不同红移处结构的人工关联，这抑制了星系透镜交叉功率谱的振幅。我们表明，通过将观测到的星系与被观测到的概率加权，可以在所有尺度上以优于~ 1%的精度减轻光纤分配对交叉功率谱的影响。但对于星系功率谱来说，情况并非如此，在k≤0.2 [h/Mpc]时，功率谱没有得到完全校正。我们发现星系-透镜交叉功率谱不受待观测星系成对概率的影响，因此基于个体概率的校正方法在所有尺度上都是足够的。
We examine the impact of fiber assignment on the measurement of galaxy clustering and its cross correlation with weak lensing fields. Unlike the past spectroscopic galaxy surveys such as Baryon Oscillation Spectroscopic Survey (BOSS), currently ongoing spectroscopic galaxy surveys such as Prime Focus Spectrograph (PFS) and Dark Energy Spectroscopic Instrument (DESI) suffer from the fiber assignment artifacts more severely because there are more target galaxies than available fibers. The previous studies found that the fiber assignment suppresses the amplitude of the galaxy power spectrum at all scales. We newly find that the fiber assignment introduces the artificial correlation of structure at different redshifts, which suppresses the amplitude of the galaxy-lensing cross power spectrum. We show that the fiber assignment effects on the cross power spectrum can be mitigated at all scales with accuracy better than ∼ 1%, by up-weighting observed galaxies with the probability to be observed. This is not the case for the galaxy power spectrum, which is not fully corrected at k ≳ 0.2 [h/Mpc]. We find that the galaxy-lensing cross power spectrum is not affected by the pairwise probability of galaxies to be observed, and thus the correction method based on the individual probability is sufficient at all scales.