标题： 模拟高红移星系中的[CII] 显示英文标题

标题： Simulated [CII] in high-z galaxies

摘要： 在红移z$\sim$4-6的恒星形成星系周围，正在报告数十千帕的[CII]发射，也被称为[CII]晕，特别是得益于ALPINE调查的统计数据。 [CII]发射预计可以追踪这些星系内部CGM中的致密冷气体。 这种发射的起源仍然存在争议。 在本文中，我们将后处理模型应用于Illustris-TNG50恒星形成星系在$z\sim$4-6，并将我们的结果与ALPINE观测进行比较。 通过结合来自紫外线背景和年轻恒星作为辐射源的C$^{+}$丰度，我们生成了模拟观测，从中提取了表面亮度（SB）轮廓。 我们发现，我们的模型预测的星系尺度上的[CII]发射值与观测结果相似，为我们的方法提供了验证。 然而，我们发现预测的内环星系介质（CGM）中的[CII]发射比观测值低一个数量级$\sim$10。 我们讨论了几种可能对这种差异有所贡献的模型限制。 当我们比较低SFR和高SFR星系的SB轮廓时，我们也发现了与观测结果的差异。 与观测结果不同，模拟显示这两个子样本之间的扩展[CII]发射没有明显差异。 这种差异可能反映了模拟中反馈模型的不足。 最后，我们的分析表明，扩展的[CII]发射可能是来自卫星星系的气体和中心星系的外流共同作用的结果，在0.6$<$R/R$_{\rm vir}<$1以内，卫星星系起着主导作用。 当前模拟的范围无法对每种贡献的重要性做出确切估计。 显示英文摘要

摘要： Extended [CII] emission on tens of kpc, also known as a [CII] halo, is being currently reported around z$\sim$4-6 star-forming galaxies, especially thanks to the statistics of the ALPINE survey. The [CII] emission is expected to trace dense cold gas in the inner CGM of these galaxies. The origin of this emission is still debated. In this paper, we present a post-processing model applied to Illustris-TNG50 star-forming galaxies at $z\sim$4-6, and we compare our results with the ALPINE observations. By incorporating C$^{+}$ abundances derived from UV background and young stars as radiation sources, we generate mock observations, from which we extract surface-brightness (SB) profiles. We found that our model predicts similar [CII] emission values on galactic scales as the observations, providing validation for our approach. However, we find that the predicted [CII] emission in the inner circumgalactic medium (CGM) falls below the observed values by a factor of $\sim$10. We discuss several model limitations that may contribute to this discrepancy. We also find discrepancies with observations when comparing SB profiles of low and high-SFR galaxies. Unlike the observations, simulations exhibit no discernible difference in the extended [CII] emission between the two subsamples. This discrepancy may reflect shortcomings in feedback model of the simulation. Finally, our analysis suggests that the extended [CII] emission is likely a result of both gas from satellite galaxies and outflows from central galaxies, with satellites playing a dominant role within 0.6$<$R/R$_{\rm vir}<$1. A firm estimate of the importance of each contribution is beyond the scope of the current simulations.