AI 中文总结
利用MeerKAT观测研究本地星系团星系，通过HI及射电连续谱追踪星际介质性质。组装星系样本并分析其光学性质，发现星系团星系早期恒星形成增强，揭示旋臂星系特点，还表明星系团星系比场星系贫HI且向中心不足增加。
AI 中文摘要
星系团中星系的演化受其与环境相互作用驱动，这深刻影响并改变多相星际介质的性质。本文利用MeerKAT观测研究三个本地（z≃0.04）星系团（IIZW108、A4059和A3558，M200≃2 - 9×10¹⁴ M⊙）约两倍Virial半径内中性和非热星际介质的性质，通过HI 21 cm线和1.4 GHz射电连续谱发射分别追踪。我们组装了61个在HI和射电连续谱中都被探测到的星系样本，包括水母星系和旋臂星系，并利用辅助数据从红外到紫外测光推导其光学性质。我们发现样本中的星系团星系平均比具有相同恒星和HI质量的场星系形成恒星的能力高约2.7倍，表明HI + 射电连续谱选择捕捉到了星系在环境演化早期阶段，此时外部压力尚未移除气体，但快速压缩增强了恒星形成和射电连续谱光度。研究还揭示初始阶段星系因旧相对论电子渗透星际介质可能有射电光度过剩。我们表明旋臂星系具有高恒星和HI质量，其特殊形态可能源于大重子质量。最后，通过对677个光学选择的星系团成员的叠加分析，我们定量表明星系团星系比场星系贫HI，且这种不足向星系团中心稳步增加，星系团中心星系平均HI质量比场星系少约3倍。
英文摘要
The evolution of galaxies in clusters is driven by their interaction with the environment, which deeply affects and alters the properties of the multi-phase interstellar medium. Here we make use of MeerKAT observations to study the properties of the neutral and nonthermal interstellar medium, traced respectively by the HI 21 cm line and by the radio continuum emission at 1.4 GHz, out to about twice the virial radius of three local ($z\simeq0.04$) galaxy clusters, namely IIZW108, A4059 and A3558, with $M_{200}\simeq2-9\times10^{14}~M_\odot$. We assemble a sample of 61 galaxies, including the so-called jellyfish and unwinding galaxies, detected in both HI and radio continuum, and derive their optical properties from IR-to-UV photometry using ancillary data. We find that cluster galaxies in our sample are on average $\sim2.7$ times more star-forming than galaxies with the same stellar and HI mass in the field, indicating that the HI + radio-continuum selection has intercepted galaxies at the very early stages of their environmental processing when the external pressure has not yet removed the gas, but the resulting fast compression has enhanced both the star formation and the radio continuum luminosity. The study also reveals that galaxies at the initial stage can features a radio luminosity excess due to the old relativistic electrons permeating the interstellar medium. We show that unwinding galaxies are characterized by high stellar and HI masses, arguing that their peculiar morphology may results from their large baryonic mass. Finally, via the stacking analysis of 677 optically-selected cluster members we quantitatively show that cluster galaxies are more HI-poor than in the field, and the deficiency steadily grows approaching the cluster center where galaxies have, on average, a factor $\sim3\times$ less HI mass than those in the field.
Comments16 pages, 11 figures. Accepted for publication on A&A on 13/7/2026
