重子反馈的双组分轮廓：流体静力学气体与弥散气体
A two-component profile of baryonic feedback: hydrostatic and diffuse gas
- Princeton University（普林斯顿大学）
- University of Cambridge（剑桥大学）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本文提出将气体分布分解为流体静力学内部分量和弥散外部分量的双组分轮廓，结合X射线与kSZ观测，为重子反馈建模提供简单可解释的框架。
AI中文摘要：
重子反馈过程在暗物质晕内部及周围重新分布气体，然而，由此产生的气体分布仍然高度不确定，限制了精确宇宙学对物质分布的预测。我们引入了一种基于物理动机的气体分布建模方法，将其分解为近似流体静力学的内部分量和弥散的外部分量。该方法利用了日益增长的观测前景：X射线测量主要探测致密的内部晕，而动力学Sunyaev-Zel'dovich（kSZ）效应对延伸到更大半径的弥散电离气体敏感。我们在重子化框架内实现了这一双组分轮廓，不过我们注意到它适用于任何大尺度气体分布模型。我们联合拟合了来自HSC-XXL和eROSITA样本的X射线气体分数测量，以及来自阿塔卡马宇宙学望远镜的BOSS CMASS星系的叠加kSZ效应测量，证明了所提出的轮廓保持了足够的灵活性。这一概念验证表明，流体静力学气体与弥散气体之间的分解为连接气体分布的互补观测提供了一个简单、物理上可解释的框架，并为未来重子反馈模型奠定了基础。
英文摘要：
Baryonic feedback processes redistribute gas within and beyond dark matter halos, however, the resulting gas distribution remains highly uncertain, limiting predictions of the matter distribution for precision cosmology. We introduce a physically motivated approach to modelling the gas distribution that decomposes it into an approximately hydrostatic inner component and a diffuse outer component. This approach takes advantage of the growing observational landscape: X-ray measurements primarily probe the dense inner halo, while the kinetic Sunyaev-Zel'dovich (kSZ) effect is sensitive to diffuse ionized gas extending to larger radii. We implement this two-component profile within the baryonification framework, though we note that it is applicable to any model of the large-scale gas distribution. We jointly fit X-ray gas-fraction measurements from the HSC-XXL and eROSITA samples with stacked kSZ effect measurements of BOSS CMASS galaxies from the Atacama Cosmology Telescope, demonstrating that the proposed profile retains sufficient flexibility. This proof-of-concept shows that a decomposition between hydrostatic and diffuse gas provides a simple, physically interpretable framework for connecting complementary observations of the gas distribution, and a foundation for future models of baryonic feedback.
