AI 中文总结
研究致密星系环境起源，通过分析附近宇宙大量星系样本，发现其环境依赖性非单调，有两个特征过密度定义三个区域，恒星质量影响显著，支持统一演化框架，表明致密星系形成有多条路径，依赖质量和环境。
AI 中文摘要
致密星系是理解星系演化的关键天体，但内部结构和环境在其形成过程中的相对作用仍不明确。本文旨在研究致密星系的丰度和熄灭如何依赖于环境，并确定其形成是否受单一演化路径或多种渠道支配。我们分析了附近宇宙中大量星系样本（$z<0.05$），其恒星质量范围为$8.2<\log(M_\star/M_\odot)<10.5$，比较致密星系和对照星系群体随局部过密度的变化。结果表明，致密星系的环境依赖性是非单调的，有两个特征过密度，即转变过密度（$\delta_t$）和临界过密度（$\delta_c$），定义了三个不同的区域。低于$\delta_t$时，致密星系相对对照群体更为丰富；在$\delta_t$和$\delta_c$之间，其相对丰度显著下降；高于$\delta_c$时，致密星系再次变得过度丰富。环境趋势显示出强烈的恒星质量依赖性，低质量星系在中等过密度下表现出最强的亏损，而高质量星系在高于$\delta_c$时主导过剩群体。此外，红色星系比例随局部过密度增加，且在致密星系中系统地更高。我们的结果支持一个统一的演化框架，其中致密星系并非来自单一演化通道，而是反映了多种路径，其相对重要性强烈依赖于恒星质量和环境。低质量致密星系与环境驱动的转变密切相关，而高质量致密星系出现在所有环境中，并在最密集区域变得越来越过度丰富。
英文摘要
Compact galaxies represent a key population for understanding galaxy evolution, but the relative role of internal structure and environment in shaping their origin remains unclear. We aim to investigate how the abundance and quenching of compact galaxies depend on environment, and to determine whether their formation is governed by a single evolutionary pathway or multiple channels. We analyse a large sample of galaxies in the nearby Universe ($z<0.05$) with stellar masses in the range $8.2<\log(M_\star/M_\odot)<10.5$, comparing compact and control populations as a function of local overdensity. We find that the environmental dependence of compact galaxies is non-monotonic, with two characteristic overdensities, the transition overdensity ($δ_t$) and the critical overdensity ($δ_c$), defining three distinct regimes. Below $δ_t$, compact galaxies are relatively more abundant than the control population, while between $δ_t$ and $δ_c$ their relative abundance decreases significantly. Above $δ_c$, compact galaxies become increasingly overabundant again. The environmental trends show a strong stellar-mass dependence, with low-mass galaxies exhibiting the strongest deficit at intermediate overdensities and high-mass galaxies dominating the excess population above $δ_c$. In addition, the red galaxy fraction increases with local overdensity and is systematically higher in compact galaxies. Our results support a unified evolutionary framework in which compact galaxies do not arise from a single evolutionary channel, but instead reflect multiple pathways whose relative importance depends strongly on stellar mass and environment. Low-mass compact galaxies are closely linked to environmentally driven transformation, whereas high-mass compact galaxies occur across all environments and become increasingly overabundant in the densest regions.
Comments13 pages, 7 figures. Accepted for publication in A&A
Journal refA&A 713, A180 (2026)
DOI：10.1051/0004-6361/202661261
