发表机构
Institut d’Astrophysique de Paris, UMR 7095, CNRS, and Sorbonne Université; Université Paris-Saclay, Université Paris Cité, CEA, CNRS, AIM; University of Bologna - Department of Physics and Astronomy “Augusto Righi” (DIFA); INAF-Osservatorio di Astrofisica e Scienza dello Spazio; Zentrum für Astronomie, Universität Heidelberg; Department of Physics, University of California, Santa Barbara; Cosmic Dawn Center (DAWN); Laboratory for Multiwavelength Astrophysics, School of Physics and Astronomy, Rochester Institute of Technology; Aix Marseille Univ, CNRS, CNES, LAM; Niels Bohr Institute（巴黎天体物理研究所; 巴黎萨克雷大学、巴黎西岱大学、法国原子能和替代能源委员会; 博洛尼亚大学; 意大利国家天体物理研究所空间科学观测站; 海德堡大学天文中心; 加州大学圣塔芭芭拉分校; 宇宙黎明中心; 罗切斯特理工学院; 艾克斯-马赛大学; 尼尔斯·玻尔研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究基于COSMOS-Web数据，结合多类数据与方法，揭示星系群环境对恒星形成的影响随宇宙时间演化，早期存在增强与抑制混合，低红移时抑制主导且低中等质量星系更明显。
AI 中文摘要
星系群追踪致密环境，其中相互作用、气体移除和吸积减少可能驱动恒星形成的猝熄。常用诊断方法追踪短时间尺度（$\boldsymbol{\tau \text{ < 100 Myr}}$）内的恒星形成，因此需要时间分辨的恒星形成历史（SFH），以在固定质量和红移下区分短暂变化与长期演化。利用COSMOS-Web数据，我们测试了星系群环境如何与恒星形成相关，这种关联如何随宇宙时间和群心距离演化，以及高富度星系群中的星系与场星系有何不同。我们结合COSMOS2025/COSMOS-Web的恒星质量、非参数SFH，以及AMICO星系群探测结果和概率成员关系，利用堆叠SFH和演化诊断，将星系群星系与匹配的场星系按归一化群心距离（$\boldsymbol{R_{\rm norm}}$）进行比较，以最富有的星系群为参考。最明显的抑制出现在$\boldsymbol{z \text{ < 1.5}}$且低至中等质量（$\boldsymbol{8.1 \text{ < } \text{log}(M_\bullet/M_\text{☉}) \text{ < 10.5}}$）的情况，群-场星系的SFH deficit可达0.8 dex。在$\boldsymbol{z \text{ > 1.5}}$时，SFH表现出弱抑制或偶尔增强，尽管存在可能的系统误差，对比结果更具异质性。径向信号也随时间演化：低红移的分布在整个半径范围内大致呈猝熄倾向，而在$\boldsymbol{z \text{ > 1}}$时出现明显的内外对比，不过在$\boldsymbol{z \text{ > 2}}$时，由于AMICO中心的不确定性增加，排序仍不确定。这些结果表明了一幅演化图景：早期的星系群更为混合，同时存在被抑制和增强的SFH；从$\boldsymbol{z \text{ < 1.5}}$开始，抑制占主导，对低至中等质量星系最为明显。这符合内部区域的星系在星系群势场中停留时间更长，更频繁地穿过致密的群内区域，且获得的原始冷气体更少，使得猝熄效应随宇宙时间逐渐变得更加明显。
英文摘要
Galaxy groups trace dense environments where interactions, gas removal, and reduced accretion may drive quenching. Common diagnostics trace star formation over short timescales ($\lesssim100$ Myr); time-resolved star formation histories (SFHs) separate recent changes from longer-term evolution at fixed mass and redshift. Using COSMOS-Web data, we test how group environment correlates with star-formation activity and its evolution with cosmic time and group-centric distance, contrasting high-richness groups with excluded field galaxies. We combine COSMOS2025/COSMOS-Web stellar masses and non-parametric SFHs with group detections and memberships from AMICO (Adaptive Matched Identifier of Clustered Objects), comparing stacked SFHs of matched group and field galaxies and measuring how the SFH offset evolves with group-centric distance for the richest groups. Massive galaxies ($\log(M_\star/M_\odot)>10.5$) show the largest offsets but are already quenched in both environments. For lower masses ($8.1<\log(M_\star/M_\odot)<10.5$), suppression is clearest at $z<1.5$ (deficit up to 0.8 dex), while at $z>1.5$ SFHs show weak suppression or occasional enhancement. The radial signal evolves similarly: quenching is broad at low $z$, the inner-outer contrast sharpens at $z\gtrsim1$, and any ordering at $z\gtrsim2$ is tentative given growing uncertainties in the AMICO centroids. These results suggest an evolving picture: groups are more mixed at early epochs, with both suppressed and occasionally elevated SFHs, partly reflecting high-$z$ uncertainties, while suppression dominates from $z\lesssim1.5$, most clearly for low-to-intermediate-mass galaxies. Inner-region galaxies likely spend more time in the group potential, undergo more passages through dense intra-group gas, and accrete less pristine cold gas, making quenching progressively clearer with cosmic time.
