标题： 突破宇宙迷雾：JWST/NIRSpec对再电离时代星系电离光子逃逸的约束 显示英文标题

标题： Breaking Through the Cosmic Fog: JWST/NIRSpec Constraints on Ionizing Photon Escape in Reionization-Era Galaxies

摘要： 电离光子的逃逸分数（fesc(LyC)）是我们理解宇宙再电离过程中的最后一个关键未知因素。 在再电离时期（EoR），由于星际介质（IGM）的不透明性，直接估计电离光子的逃逸分数（fesc）是不可能的。 然而，高fesc会在星系的光谱中留下明显的痕迹，由于星云线和连续谱发射的减少，这也导致了更蓝的紫外连续谱斜率（betaUV）。 在这里，我们利用DAWN JWST档案中的大量深场JWST/NIRSpec光谱，分析了5 < zspec < 10之间的超过1'400个星系，并基于增强的栅栏模型的SED拟合来限制它们的fesc。 我们通过贝叶斯因子分析识别出71个高置信度源，这些源显示出显著的fesc，强烈支持fesc > 0而非fesc = 0的解。 我们将这个高逃逸子集的特征与母样本以及已建立的诊断方法（包括betaUV斜率、O32和恒星形成率表面密度（SigmaSFR））进行了比较。 对于整体样本，我们发现大多数源的逃逸分数较低（<1%），然而，一小部分源似乎向IGM发射了大量的电离光子，使得平均fesc被发现约为10%，这是星系驱动再电离所需要的。 尽管关于近期爆发性和低金属丰度下恒星的电离光子输出仍存在不确定性，但我们的结果展示了JWST/NIRSpec独特的能力，可以识别单个LyC泄漏源，测量平均fesc，从而约束宇宙再电离的驱动因素。 显示英文摘要

摘要： The escape fraction of Lyman continuum photons (fesc(LyC)) is the last key unknown in our understanding of cosmic reionization. Directly estimating the escape fraction (fesc) of ionizing photons in the epoch of reionization (EoR) is impossible, due to the opacity of the intergalactic medium (IGM). However, a high fesc leaves clear imprints in the spectrum of a galaxy, due to reduced nebular line and continuum emission, which also leads to bluer UV continuum slopes (betaUV). Here, we exploit the large archive of deep JWST/NIRSpec spectra from the DAWN JWST Archive to analyze over 1'400 galaxies at 5 < zspec < 10 and constrain their fesc based on SED fitting enhanced with a picket fence model. We identify 71 high-confidence sources with significant fesc based on Bayes factor analysis strongly favouring fesc > 0 over fesc = 0 solutions. We compare the characteristics of this high-escape subset against both the parent sample and established diagnostics including betaUV slope, O32, and SFR surface density (SigmaSFR). For the overall sample, we find that most sources have a low escape fraction (<1%), however, a small subset of sources seems to emit a large number of their ionizing photons into the IGM, such that the average fesc is found to be ~10%, as needed for galaxies to drive reionization. Although uncertainties remain regarding recent burstiness and the intrinsic stellar ionizing photon output at low metallicities, our results demonstrate the unique capability of JWST/NIRSpec to identify individual LyC leakers, measure average fesc and thus constrain the drivers of cosmic reionization.