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arXiv 2401.02572astro-ph.GA
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Ly$α$发射作为矮星系中反馈调控的LyC逃逸的灵敏探针

Ly$α$ emission as a sensitive probe of feedback-regulated LyC escape from dwarf galaxies

Yuxuan Yuan, Sergio Martin-Alvarez, Martin G. Haehnelt, Thibault Garel, Debora Sijacki

AI总结:

本研究利用PANDORA高分辨率矮星系模拟与\textsc{RASCAS}辐射转移后处理,揭示Ly$α$发射与LyC逃逸分数的普遍关联,为通过Ly$α$观测约束矮星系反馈调控的LyC逃逸、验证其宇宙再电离作用提供了依据。

摘要:

Ly$α$发射是追踪演化星系的生命周期以及电离光子逃逸的极具信息量的示踪剂。然而,Ly$α$发射的理论研究通常受限于数值分辨率不足、物理模型集不完整以及视线(LOS)统计效果不佳。为了克服这些限制,本文采用了全新的PANDORA高分辨率矮星系模拟套件,该套件包含一套全面的、最先进的物理模型,涵盖电离辐射、磁场、超新星反馈和宇宙射线。我们使用辐射转移代码\textsc{RASCAS}对模拟结果进行后处理,生成合成观测结果,并与Ly$α$发射体的观测特性进行比较。我们模拟得到的Ly$α$晕比本征发射的空间起源区域更延展,且我们得到的Ly$α$发射光谱参数的空间分辨图对中性氢的底层空间分布和运动学非常敏感。Ly$α$和LyC发射沿不同视线呈现出差异极大的特征,这取决于每条视线与恒星反馈产生的低密度通道的相交情况。通过比较采用不同物理机制模拟的星系,我们发现Ly$α$特征存在系统性偏移,这由反馈强度的不同水平以及中性气体的团块性决定。尽管存在这种差异,且无论每个模型包含的物理机制有何不同,我们都发现Ly$α$观测量与LyC逃逸分数之间存在普遍相关性,证明了Ly$α$与LyC发射之间存在稳固的联系。因此,对大样本矮星系的Ly$α$观测将能对其恒星反馈调控的LyC逃逸给出强约束,并证实矮星系在宇宙再电离中的重要作用。

英文摘要:

Ly$α$ emission is an exceptionally informative tracer of the life cycle of evolving galaxies and the escape of ionising photons. However, theoretical studies of Ly$α$ emission are often limited by insufficient numerical resolution, incomplete sets of physical models, and poor line-of-sight (LOS) statistics. To overcome such limitations, we utilize here the novel PANDORA suite of high-resolution dwarf galaxy simulations that include a comprehensive set of state-of-the-art physical models for ionizing radiation, magnetic fields, supernova feedback and cosmic rays. We post-process the simulations with the radiative transfer code \textsc{RASCAS} to generate synthetic observations and compare to observed properties of Ly$α$ emitters. Our simulated Ly$α$ haloes are more extended than the spatial region from which the intrinsic emission emanates and our spatially resolved maps of spectral parameters of the Ly$α$ emission are very sensitive to the underlying spatial distribution and kinematics of neutral hydrogen. Ly$α$ and LyC emission display strongly varying signatures along different LOS depending on how each LOS intersects low-density channels generated by stellar feedback. Comparing galaxies simulated with different physics, we find the Ly$α$ signatures to exhibit systematic offsets determined by the different levels of feedback strength and the clumpiness of the neutral gas. Despite this variance, and regardless of the different physics included in each model, we find universal correlations between Ly$α$ observables and LyC escape fraction, demonstrating a robust connection between Ly$α$ and LyC emission. Ly$α$ observations from a large sample of dwarf galaxies should thus give strong constraints on their stellar feedback-regulated LyC escape and confirm their important role for the reionization of the Universe.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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