发表机构
INAF-Osservatorio Astronomico di Brera（INAF-布拉耶天文台）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究利用 SPT SZ 星系团样本和分层贝叶斯方法，测量了压力轮廓的标度与内在弥散，发现轮廓比先前估计低约40%，并约束了自相似演化的偏离。
AI 中文摘要
星系团内介质的 thermal 压力轮廓对星系团宇宙学以及理解星系团天体物理至关重要。我们确定了 Sunyaev-Zel'dovich (SZ) 选样星系团的总体平均压力轮廓，刻画了其内在弥散，并测量了其随质量与红移的标度关系。我们从 South Pole Telescope (SPT) SZ 星表中选取了 60 个星系团，红移范围 $0.08<z<0.6$，要求 Planck-SPT Compton-$y$ 图具有高信噪比和 5 个分辨率元。我们使用具有受限三次样条的分层贝叶斯框架，从 Compton-$y$ 图建模球对称三维压力轮廓。我们采用了更新的弱引力透镜标定的 Compton-$Y$--质量标度关系，从而有效消除了推断质量中的静水力学质量偏差。我们的模型考虑了星系团之间的轮廓变化、视线方向的前景和背景贡献，以及来自本质上不同星系团或投影效应的离群点。代码公开可用。我们推导了总体平均压力轮廓，发现在中间半径（$0.4 \le r/r_{500} \le 0.7$）处内在弥散最小。由于无偏质量标度，我们的压力轮廓在所有半径处比先前估计低约 40%。我们发现了提示性但非结论性的证据，表明所采用的质量依赖可能需要修订，即移除 Arnaud 等人 2010 年引入的额外 $M^{0.12}$ 标度。我们将平均轮廓对自相似演化的偏离限制在小于 0.1--0.2 dex，并将内在弥散的演化限制为每 $\Delta z=0.1$ 小于 8%。
英文摘要
[shortened] The thermal pressure profile of the intracluster medium is critical for cluster cosmology and understanding galaxy-cluster astrophysics. We determine the population-averaged pressure profile of Sunyaev-Zel'dovich (SZ) selected clusters, characterize its intrinsic scatter, and measure its scaling with mass and redshift. We select 60 clusters from the South Pole Telescope (SPT) SZ catalog with $0.08<z<0.6$, requiring high signal-to-noise and 5 element resolution on Planck-SPT Compton-$y$ maps. We model spherical three-dimensional pressure profiles from the Compton-$y$ maps using a hierarchical Bayesian framework with restricted cubic splines. We adopt an updated weak-lensing-calibrated Compton-$Y$--mass scaling relation, effectively removing hydrostatic mass bias from the inferred masses. Our model accounts for cluster-to-cluster profile variations, line-of-sight foreground and background contributions, and outliers from intrinsically distinct clusters or projection effects. The code is publicly available. We derive the population-averaged pressure profile and find minimal intrinsic scatter at intermediate radii ($0.4 \le r/r_{500} \le 0.7$). Our pressure profile is approximately 40\% lower than previous estimates at all radii, due to the unbiased mass scaling. We find suggestive, though not conclusive, evidence that the adopted mass dependence may require revision by removing the additional $M^{0.12}$ scaling introduced by Arnaud et al. 2010. We constrain departures from self-similar evolution in the mean profile to less than 0.1--0.2 dex and evolution of the intrinsic scatter to less than 8\% per $Δz=0.1$.
CommentsA&A, in press
