AI 中文总结
该研究旨在测量宇宙正午LAEs的恒星形成随机性，通过非参数高斯过程重建其SFH，引入恒星形成随机性图，利用高斯混合模型分解短时间SFR比率，揭示与经验原型一致的三个群体，可总结LAEs的恒星质量聚集情况。
AI 中文摘要
在这项工作中，我们旨在测量宇宙正午莱曼α发射星系（LAEs）的恒星形成随机性。我们从HETDEX巡天中在COSMOS场识别出270个LAEs，并利用CANDELS的静止紫外到近红外测光数据。对每个LAE，我们使用密集基方法进行非参数高斯过程恒星形成历史（SFH）重建。我们的HETDEX LAE样本能很好地由为ODIN LAEs定义的三种SFH原型描述。传统的SFR$_{100}-M_*$图不能充分体现第一爆发LAEs快速上升的恒星形成率，促使我们使用SFR$_{10}-M_*$。我们引入恒星形成随机性图这一诊断工具，通过消除红移演化的混杂因素，用高斯混合模型将短时间SFR比率分解为亚群，揭示出与经验LAE SFH原型一致的三个群体，可据此总结LAEs的整体恒星质量聚集情况。
英文摘要
In this work, we aim to measure the star formation stochasticity of Lyman Alpha Emitting Galaxies (LAEs) at Cosmic Noon. We identify 270 LAEs from the HETDEX Survey in the COSMOS field with rest-UV-through-NIR photometry from CANDELS\null. For each LAE, we perform non-parametric gaussian-process star formation history (SFH) reconstruction using the Dense Basis method. Our HETDEX LAE sample is described well by the three SFH archetypes defined for ODIN LAEs in Firestone et al. 2025 with comparable frequency: First Burst, Dominant Burst, and Nondominant Burst. The rapidly rising Star Formation Rates (SFRs) of First Burst LAEs are not adequately represented in traditional SFR$_{100}-M_*$ diagrams, where SFR$_{100}$ is averaged over the most recent 100Myr. This motivates the usage of SFR$_{10}-M_*$, where SFR$_{10}$ is averaged over the most recent 10Myr. We introduce the Star Formation Stochasticity Diagram, a diagnostic tool that probes variations in galaxies' SFRs across cosmic time. By eliminating the confounding factor of redshift evolution, we are able to employ a gaussian mixture model to decompose our ratio of short- vs.long-term SFR into statistically motivated sub-populations. This agnostic component decomposition reveals three populations consistent with the empirical LAE SFH archetypes. We can, therefore, summarize the overall stellar mass assembly of LAEs with this ratio, even without viewing their full star formation histories.
Comments13 pages; 4 figures; submitted to ApJL
