标题： 卤族红移相关选择效应对红移空间功率谱的影响 显示英文标题

标题： The impact of the redshift-dependent selection effect of halos on the redshift-space power spectrum

摘要： 在大范围的星系光谱巡天中，几乎不可能针对诸如恒星质量与宿主暗晕质量等星系性质，在不同红移范围内获得一个均匀的星系样本。 尽管存在选择效应，但在大多数分析中，理论模板通常假设单一示踪物来与测量得到的聚类量进行比较。 我们通过解析方法证明，这种选择效应不可避免地会在从线性尺度到非线性尺度的红移空间功率谱上引入偏差。 为了定量评估选择效应对结果的影响，我们通过从N体模拟中的暗晕构建模拟星系目录，选取高于红移相关质量阈值的暗晕，使得这些暗晕的红移分布，即 $n(z)$，与类似SDSS星系的红移分布相匹配。 我们发现，对于类似SDSS星系样本中 $n_{\rm g}(z)$的情况，与单一质量阈值（因此单一示踪物）样本相比，选择效应对红移空间功率谱的单极子和四极子矩分别引起的分数变化仅为约1%和2%，分别对应于 $k\lesssim 0.3~h{\rm{Mpc}}^{-1}$。 此外，我们认为，只要红移相关的选择效应较为温和，那么使用Fisher矩阵法估算宇宙学参数时，选择效应对结果产生的偏差不太可能显著。 显示英文摘要

摘要： In a wide-area spectroscopic survey of galaxies, it is nearly impossible to obtain a homogeneous sample of galaxies with respect to galaxy properties such as stellar mass and host halo mass across a range of redshifts. Despite the selection effect, theoretical templates in most analyses assume single tracers when compared with the measured clustering quantities. We demonstrate analytically that the selection effect inevitably introduces a bias in the redshift-space power spectrum on scales from linear to nonlinear scales. To quantitatively assess the impact of the selection effect, we construct mock galaxy catalogs from halos in N-body simulations by selecting halos above redshift-dependent mass thresholds such that the resulting redshift distribution of the halos, $n(z)$, matches that of SDSS-like galaxies. We find that the selection effect causes fractional changes of up to only 1% and 2% in the monopole and quadrupole moments of the redshift-space power spectrum at $k\lesssim 0.3~h{\rm{Mpc}}^{-1}$, respectively, compared to the moments for the single mass-threshold (therefore single tracer) sample, for $n_{\rm g}(z)$ of the SDSS-like galaxy samples. We also argue that the selection effect is unlikely to cause a significant bias in the estimation of cosmological parameters using the Fisher matrix method, provided that the redshift-dependent selection effect is modest.