论文标题
选择的效果 - 相关性和投影引起的群集质量测量偏差的故事
The effect of selection -- a tale of cluster mass measurement bias induced by correlation and projection
论文作者
论文摘要
黑暗能源调查使用星系簇的宇宙学分析最近发现了一个以前未知的选择效应的问题，影响了弱透镜质量估计。在这封信中，我们使用Illustris-TNG模拟来证明，由于不同可观察到的不同观察值之间的投影和相关性，因此对星系计数进行选择会诱导选择效果。我们计算了暗物质光环的弱透镜样质量估计，并检查其预计的subhalo计数。在2D投影的空间中，测量比真理更大的光环具有更高的subhalo计数。因此，沿着视线的投影产生了与群集质量测量偏差相关的群集可观察到的物体，从而，当该相关的可观察到的群集选择群集时，这又会产生质量测量偏差。我们证明了使用可观察的质量测量相关性在正向模型中预测偏差。
Cosmology analyses using galaxy clusters by the Dark Energy Survey have recently uncovered an issue of previously unknown selection effect affecting weak lensing mass estimates. In this letter, we use the Illustris-TNG simulation to demonstrate that selecting on galaxy counts induces a selection effect because of projection and correlation between different observables. We compute the weak-lensing-like projected mass estimations of dark matter halos and examine their projected subhalo counts. In the 2-D projected space, halos that are measured as more massive than truth have higher subhalo counts. Thus, projection along the line of sight creates cluster observables that are correlated with cluster mass measurement deviations, which in turn creates a mass measurement bias when the clusters are selected by this correlated observable. We demonstrate that the bias is predicted in a forward model using the observable-mass measurement correlation.
