AI 中文总结
研究通过结合逐云电离建模与星系旋转运动学，探讨星系际介质中金属丰度与方位角和角动量的关系，发现其金属丰度、运动学和电离特征与贫金属流入及再循环吸积有关，揭示重子循环对金属丰度和角动量的印记及CGM气体起源。
AI 中文摘要
星系际介质（CGM）的方位和运动学结构常被解释为平面吸积和双极外流，但这种图景的直接金属丰度证据仍不明确。我们将逐云电离建模与多相星系晕调查中21个星系的星系旋转运动学相结合，研究金属丰度如何依赖于方位角和角动量。我们发现，与盘旋转运动学一致的低电离云在投影主轴附近（$\Phi<30^\circ$）的金属丰度比在较大方位角处低约0.5 dex。主轴云还表现出更高的中性氢柱密度、更高的密度以及与较大方位角处的云相比减少的非热线展宽。相比之下，较高电离阶段对方位角没有显著的金属丰度依赖性，并且与共旋转主轴低电离云相比具有更低的柱密度、更低的密度、更高的温度和更宽的线宽。这些综合的金属丰度 - 运动学 - 电离特征与沿着盘平面动态冷的贫金属流入以及在较大方位角处富集的、更湍流的气体一致，后者可能追踪角动量支持的再循环吸积，并嵌入在动态复杂的较暖相中。这些结果表明，金属丰度和角动量由重子循环共同印记，并且两者都是揭示CGM气体物理起源所必需的。
英文摘要
The azimuthal and kinematic structure of the CGM is often interpreted as planar accretion and bipolar outflows, yet direct metallicity evidence for this picture remains ambiguous. We combine cloud-by-cloud ionisation modelling with galaxy rotation kinematics for 21 galaxies from the Multiphase Galaxy Halos Survey to investigate how metallicity depends on azimuthal angle and angular momentum. We find that low-ionisation clouds kinematically consistent with disk rotation have ~0.5 dex lower metallicity near the projected major axis ($Φ<30^\circ$) than at larger azimuthal angles. Major-axis clouds also exhibit higher N(HI), higher density, and reduced non-thermal line broadening compared to clouds at larger azimuthal angles. In contrast, the higher-ionisation phase shows no significant metallicity dependence on azimuthal angle and has lower column densities, lower densities, higher temperatures, and broader line widths than the co-rotating major-axis low-ionisation clouds. These combined metallicity--kinematic--ionisation signatures are consistent with dynamically cold, metal-poor inflow along the disk plane and enriched, more turbulent gas at larger azimuthal angles that likely traces angular-momentum-supported recycled accretion, embedded within a dynamically complex warmer phase. These results show that metallicity and angular momentum are jointly imprinted by the baryon cycle and are both required to uncover the physical origins of CGM gas.
Comments7 pages, 2 figures, 1 table. Accepted to MNRAS on July 14, 2026
