AI 中文总结
本文综述了第三星族星形成的理论预期和观测策略，包括近场宇宙学、直接搜索极贫金属星形成复合体及高红移硬电离谱特征等，结合JWST等新观测手段，为寻找第一代星开辟了“黄金时代”。
AI 中文摘要
寻找第一代（第三星族或Pop III）星是天文学的基本任务之一，旨在揭示早期宇宙恒星形成中缺失的环节。然而，它们的初始质量函数、形成位置和反馈，以及向富金属恒星形成过渡的时间和拓扑结构仍然高度不确定。由于寿命短且暗淡，它们独特光谱特征的可观测性也存在争议。本综述总结了当前对Pop III星形成的理论预期，以及为限制其宇宙时间属性而采用的主要观测策略，包括近场宇宙学研究、直接搜索极贫金属星形成复合体和/或高红移及中等红移处的硬电离谱特征，以及识别直至宇宙黎明的Pop III活动的展望。JWST光谱学、时域搜索、透镜巡天、恒星考古、吸收线研究以及改进的模拟相结合，正在产生越来越多的观测候选体，并缩小了第一代星的允许参数空间，为Pop III搜索的“黄金时代”奠定了基础。
英文摘要
Finding the first (Population III or Pop III) stars is one of the fundamental quests of astronomy, aiming to deliver the missing link in how stars form at early cosmic times. Yet their initial mass function, formation sites and feedback remain highly uncertain, as well as the timing and topology of the transition to metal-enriched star formation. The observability of their peculiar spectral features is also debated, due to their short lifetime and faintness. This review summarizes current theoretical expectations for Pop III star formation, and the main observational strategies that have been adopted to constrain their properties across cosmic time, including near-field cosmology studies, direct searches for extremely metal-poor star-forming complexes and/or hard-ionizing spectral signatures at high and intermediate redshifts, and prospects for identifying Pop III activity up to Cosmic Dawn. The combination of JWST spectroscopy, time-domain searches, lensing surveys, stellar archaeology, absorption-line studies, as well as improved simulations, is yielding a growing number of observational candidates and narrowing the allowed parameter space for the first stars, setting the stage for a ``golden era'' of Pop III searches.
Comments29 pages, 14 figures, 3 tables. Proceeding of "The search for Pop III stars" session of the CSI: Sesto workshop, January 26-30 2026. Published in the Open Journal of Astrophysics. Main change: extended discussion on Pop III transients in Sec. 5
