论文标题

量化投影抑制群集逃生速度曲线

Quantifying the Projected Suppression of Cluster Escape Velocity Profiles

论文作者

Halenka, Vitali, Miller, Christopher J., Vansickle, Paige

论文摘要

星系簇的3D径向逃逸速度曲线被认为是限制加速宇宙中质量概况和宇宙学参数的有前途和竞争的工具。但是,与基础的3D径向(或切向)逃逸曲线相比,已知观察到的视线逃逸曲线被抑制。过去的工作表明,相位数据中的速度各向异性是根本原因。取而代之的是,我们发现观察到的抑制是来自相位空间的统计不采样,并且可以从投影数据中准确地推断出3D径向逃生边缘。我们为这种抑制构建了一个分析模型,该模型仅需要在天空投影范围内观察到的星系$ n $的数量,$ 0.3 \ le r_ \ r_ \ perp/r_ {200,\ text {crience}}} \ le 1 $。径向平均的抑制函数是逆权法律$ \ langle z_ \ text {v} \ rangle = 1 +(n_0/n)^λ$,$ n_0 = 17.818 $和$λ= 0.362 $。我们使用$ n $体体模拟测试模型,使用暗物质颗粒,subhalos和半分析星系作为相位空间示踪剂,并找到了极好的一致性。我们还评估了来自宇宙学的系统偏见($ω_λ$,$ h_0 $),群集质量($ m_ {200,\ text {critical}} $)和速度各向异性($β$)。我们发现,在$ \ langle z_ \ text {v} \ rangle $ of $ 2.7 \%$的$ \ langle z_ \ text {v} \ rangle $ of $ \ langle z_ \ text {v} \%$中,在大范围上有所不同。这些系统学是高度尺寸的(至少为13.7倍),从$ n $开始抑制。

The 3D radial escape-velocity profile of galaxy clusters has been suggested to be a promising and competitive tool for constraining mass profiles and cosmological parameters in an accelerating universe. However, the observed line-of-sight escape profile is known to be suppressed compared to the underlying 3D radial (or tangential) escape profile. Past work has suggested that velocity anisotropy in the phase-space data is the root cause. Instead, we find that the observed suppression is from the statistical undersampling of the phase spaces and that the 3D radial escape edge can be accurately inferred from projected data. We build an analytical model for this suppression that only requires the number of observed galaxies $N$ in the phase-space data within the sky-projected range $0.3 \le r_\perp/R_{200, \text{critical}} \le 1$. The radially averaged suppression function is an inverse power law $\langle Z_\text{v} \rangle = 1 + (N_0/N)^λ$ with $N_0 = 17.818$ and $λ= 0.362$. We test our model with $N$-body simulations, using dark matter particles, subhalos, and semianalytic galaxies as the phase-space tracers, and find excellent agreement. We also assess the model for systematic biases from cosmology ($Ω_Λ$, $H_0$), cluster mass ($M_{200, \text{critical}}$), and velocity anisotropy ($β$). We find that varying these parameters over large ranges can impart a maximal additional fractional change in $\langle Z_\text{v} \rangle$ of $2.7\%$. These systematics are highly subdominant (by at least a factor of 13.7) to the suppression from $N$.

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