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arXiv 2409.04537astro-ph.GA
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Lyman-$α$晕的本征分布

The Intrinsic Distribution of Lyman-$α$ Halos

John Pharo, Lutz Wisotzki, Tanya Urrutia, Roland Bacon, Ismael Pessa, Ramona Augustin, Ilias Goovaerts, Daria Kozlova, Haruka Kusakabe, Héctor Salas, Daniil Smi… 展开作者

John Pharo, Lutz Wisotzki, Tanya Urrutia, Roland Bacon, Ismael Pessa, Ramona Augustin, Ilias Goovaerts, Daria Kozlova, Haruka Kusakabe, Héctor Salas, Daniil Smirnov, Tran Thi Thai, Eloïse Vitte

AI总结:

本文通过构建Lyman-$α$晕的三维空间-光谱模型并推导选择函数,利用145个UDF-Mosaic样本获得了$3<z<5$ LAH关键晕参数的本征分布,揭示了观测对延展晕标长LAH的低估。

摘要:

恒星形成星系中Lyman-$α$光子的发射与逃逸由发射光子与星系星际及环星系气体之间的复杂相互作用决定,这使得Lyman-$α$发射体(LAEs)通常并非表现为点源,而是呈现为具有复杂光谱轮廓的空间延展晕。我们开发了一个Lyman-$α$晕(LAHs)的三维空间-光谱模型,以复现积分视场光谱观测中的LAH观测结果,例如使用VLT/MUSE进行的观测。该模型的轮廓是6个关键晕参数的函数:晕和致密源的指数标长($r_{sH}$和$r_{sC}$)、晕流量占比($f_H$)、致密成分椭率($q$)、谱线宽度($σ$)以及谱线偏度参数($γ$)。我们将一系列模型LAH放入反映MUSE UDF-Mosaic巡天观测条件的数据立方体中,测试其探测可恢复性,并确定在给定的中心波长和内禀谱线光度下,$σ$、$r_{sH}$和$f_H$预计对整体LAH的可探测性具有最显著的影响。我们开发了一个覆盖这些晕参数网格的通用选择函数模型,并利用145个具有已测量晕参数的UDF-Mosaic LAH样本,推导出$3<z<5$ LAH的$σ$、$r_{sH}$和$f_H$值的完备性校正后的本征分布。我们给出了这些分布的最佳拟合函数形式,以及经仪器线扩散函数(LSF)展宽校正后的$σ$分布,从而展示了本征群体的物理谱线扩散分布。最后,我们讨论了这些分布对Ly$α$发射穿过环星系介质的启示,发现与内禀群体相比,观测会低估具有延展晕标长的LAH数量。

英文摘要:

The emission and escape of Lyman-$α$ photons from star-forming galaxies is determined through complex interactions between the emitted photons and a galaxy's interstellar and circumgalactic gas, causing Lyman-$α$ emitters (LAEs) to commonly appear not as point sources but in spatially extended halos with complex spectral profiles. We develop a 3D spatial-spectral model of Lyman-$α$ halos (LAHs) to replicate LAH observations in integral field spectroscopic studies, such as those made with VLT/MUSE. The profile of this model is a function of 6 key halo properties: the halo- and compact-source exponential scale lengths ($r_{sH}$ and $r_{sC}$), the halo flux fraction ($f_H$), the compact component ellipticity ($q$), the spectral line width ($σ$), and the spectral line skewness parameter ($γ$). Placing a series of model LAHs into datacubes reflecting observing conditions in the MUSE UDF-Mosaic survey, we test their detection recoverability and determine that $σ$, $r_{sH}$, and $f_H$ are expected to have the most significant effect on the detectability of the overall LAH at a given central wavelength and intrinsic line luminosity. We develop a general selection function model spanning a grid of these halo parameters, and with a sample of 145 UDF-Mosaic LAHs with measured halo properties, we derive completeness-corrected, intrinsic distributions of the values of $σ$, $r_{sH}$, and $f_H$ for $3<z<5$ LAHs. We present best-fit functional forms of the distributions, and a $σ$ distribution corrected for instrumental line-spread function (LSF) broadening, and thereby show the physical line spread distribution of the intrinsic population. Finally, we discuss implications of these distributions for Ly$α$ emission through the circumgalactic medium, finding that observations undercount LAHs with extended halo scale lengths compared to the intrinsic population.

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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