发表机构
Technion – Israel Institute of Technology（以色列理工学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究利用Illustris和IllustrisTNG模拟，结合Hα光度函数，在z~1处约束重子反馈，发现低反馈的IllustrisTNG模拟与观测更吻合，揭示了相关探测手段的综合约束能力。
AI 中文摘要
重子反馈仍是星系形成模型中的主要不确定性之一，因为它会影响星际介质（ISM）和恒星形成。我们利用Illustris和IllustrisTNG模拟研究其对Hα光度函数（LF）的影响，纳入了与方向相关的尘埃消光以及对莱曼系列光子传播的物理解释处理。我们对三类Hα发射源进行建模：恒星形成H II区、弥散ISM中的碰撞激发与复合，以及AGN诱导的弥散气体光激发。这些模型通过一个将恒星形成率与H II区Hα光度关联的单一自由参数，针对z~1-1.5处观测到的Hα LF进行校准。我们发现，在两套模拟中，弥散气体的发射贡献了总Hα光度的约1%-10%。AGN光激发仅对LF的亮端产生适度增强，不过它主导了Illustris星系中L_Hα≳3×10^42 erg s^-1的Hα发射。低反馈的IllustrisTNG模拟对所有考虑的发射模型都与观测到的LF吻合良好，而高反馈的Illustris模拟无法在z~1处同时重现LF的暗端和亮端。Hα LF与堆叠kSZ测量之间的这种张力，凸显了这些探测手段在约束重子反馈、气体性质以及发射线星系相关物理之间相互作用方面的综合能力。
英文摘要
Baryonic feedback remains one of the primary uncertainties in galaxy formation models because of its impact on the interstellar medium (ISM) and star formation. We investigate its effect on the H$α$ luminosity function (LF) using the Illustris and IllustrisTNG simulations, incorporating direction-dependent dust attenuation and a physically motivated treatment of the propagation of Lyman-series photons. We model three sources of H$α$ emission: star-forming H II regions, collisional excitation and recombination in the diffuse ISM, and AGN-induced photo-excitation of diffuse gas. The models are calibrated against observed H$α$ LFs at $z\sim 1-1.5$ using a single free parameter relating the star formation rate to the H II-region H$α$ luminosity. We find that emission from diffuse gas contributes $\sim 1\%-10\%$ of the total H$α$ luminosity in both simulation sets. AGN photo-excitation produces only a modest enhancement of the bright end of the LF, although it dominates the H$α$ emission of Illustris galaxies with $L_{\text{H}α}\gtrsim 3\times10^{42}\ \rm{erg \ s^{-1}}$. The low-feedback IllustrisTNG simulations provide good agreement with the observed LFs for all emission models considered, whereas the high-feedback Illustris simulation fails to simultaneously reproduce the faint and bright ends of the LF at $z\sim 1$. This tension between H$α$ LFs and stacked kSZ measurements highlights the combined power of these probes for constraining the interplay between baryonic feedback, gas properties, and the physics governing emission-line galaxies.
