发表机构
University of Florida; University of Copenhagen; Technical University of Denmark; University of Virginia; INAF, Osservatorio Astronomico di Trieste; Institute for Fundamental Physics of the Universe; Jet Propulsion Laboratory, California Institute of Technology; University of Texas at Austin; University of Massachusetts, Amherst; European Southern Observatory; Centro de Astrobiologia (CAB), CSIC-INTA（佛罗里达大学; 哥本哈根大学; 丹麦技术大学; 弗吉尼亚大学; 意大利国家天体物理研究所的的里雅斯特天文台; 宇宙基础物理研究所; 加州理工学院喷气推进实验室; 德克萨斯大学奥斯汀分校; 马萨诸塞大学阿默斯特分校; 欧洲南方天文台; 西班牙国家研究委员会-国家航空航天技术研究所天体生物学中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
我们通过大体积极宇宙学模拟结合半解析模型和辐射转移代码，首次在宽红移范围建模PAH丰度与辐射，再现观测相关性，支持PAH自上而下形成，为未来观测提供预测。
AI 中文摘要
我们首次展示了覆盖宽广宇宙时间范围（$0 < z \lesssim 6$）的大体积极宇宙学模拟，该模拟包含对多环芳烃（PAHs）丰度及其发光辐射的建模。该模拟基于一个半解析模型（SAM），其中包含对尘埃粒径分布的处理，PAHs被识别为存在于星系弥散星际介质中的最小碳质颗粒（$< 15$ Å）。PAH辐射通过对模拟输出使用辐射转移代码GRASIL进行后处理来计算。在我们的模型中，恒星仅注入大颗粒，PAH丰度源于星际介质中尘埃颗粒的生长和碎裂，自然地再现了观测到的PAH质量分数（$q_{\rm PAH}$）与金属丰度及比恒星形成率（sSFR）之间的相关性。我们推导出一个关系式，用以从$L_{\rm PAH}$、$L_{\rm IR}$和sSFR推断$q_{\rm PAH}$，其散射相对较小（约1.3倍）。模拟的PAH辐射与恒星形成率（SFR）和分子气体含量等关键星系性质相关性良好，并再现了观测约束。综合来看，这些结果支持PAHs自上而下形成情景的可行性。我们将模型预测扩展到更高红移，这可用于未来任务如PRIMA。这项工作是将PAH观测用作研究星系演化工具的重要一步。
英文摘要
We present the first large-volume cosmological simulation of galaxy evolution with a model for the abundance and luminous emission of Polycyclic Aromatic Hydrocarbons (PAHs) across a wide range of cosmic time ($0 < z \lesssim 6$). The simulation is built on a semi-analytic model (SAM) that includes a treatment of dust size distribution, with PAHs being identified with the smallest carbonaceous grains ($< 15$ A) residing in the diffuse ISM of galaxies. PAH emission is computed by post-processing the simulation output with the radiative transfer code GRASIL. In our model, where stars only inject large grains, the PAH abundance emerges from the growth and shattering of dust grains in the ISM, naturally reproducing the observed correlation between the PAH mass fraction ($q_{\rm PAH}$) and both metallicity and specific star formation rate (sSFR). We derive a relation to infer $q_{\rm PAH}$ from $L_{\rm PAH}$, $L_{\rm IR}$, and sSFR, with a relatively small scatter (a factor of $\approx 1.3$). Simulated PAH emission correlates well with key galaxy properties such as SFR and molecular gas content, and reproduces observational constraints. Taken together, these results support the viability of a top-down formation scenario for PAHs. We extend our model predictions to higher redshifts, which can be exploited for future missions such as PRIMA. This work is a significant step toward leveraging PAH observations as a tool for studying galaxy evolution.
Comments24 pages, 14 figures. To be submitted. Comments welcome!
