标题： COS-EDGES：边缘星系周围多相CGM的共旋转和运动学分层 显示英文标题

标题： COS-EDGES: Co-rotation and Kinematic Stratification of the Multi-Phase CGM Around Edge-On Galaxies

摘要： 我们展示了来自COS-EDGES调查的首批结果，该调查旨在研究在红移约0.2的九个孤立的边缘朝向星系中，星际介质（ISM）与多相星系晕介质（CGM）之间的运动学联系，每个星系均通过背景类星体在其主轴方向上进行探测，影响参数为13-38kpc。利用VLT/UVES和HST/COS类星体光谱，我们分析了相对于Keck/LRIS和Magellan/MagE光谱中的星系旋转曲线的MgI、MgII、HI、CII、CIII和OVI吸收。我们发现，在较低的$D/R_{vir}$（$D/R_{vir}\leq 0.2$）下，所有离子的吸收中有超过80%位于与系统速度匹配的盘旋转侧，光学深度加权中位速度（$v_{abs}$）与峰值旋转速度一致。在较高的$D/R_{vir}$（$D/R_{vir} > 0.2$）下，不同电离状态的气体动力学出现分歧：对于低电离气体，共旋转吸收量仍大于80%，但$v_{abs}$下降到星系旋转速度的60%。对于高电离气体（OVI），只有60%的吸收与共旋转一致，且$v_{abs}$下降到旋转速度的20%。 此外，低电离气体对应的总光学深度50%的速度宽度（$\Delta v_{50}$）在内晕中比在更大半径处大1.8倍，而对于CIII和OVI（$\Delta v_{50}$）则随距离变化而保持不变。 这些结果表明，CGM的动力学结构具有径向依赖性：内晕包含与盘旋转紧密耦合的冷却、动态宽气体，而在0.2$R_{vir}$以外，尤其是由OVI和HI所追踪的区域，CGM表现出较弱的旋转对齐和较低的速度弥散。 因此，低电离气体可能追踪扩展的共旋转气体、流入和/或再循环吸积，而高电离气体则反映了共旋转、滞后、离散碰撞电离结构的混合，表明多相CGM的动力学分层。 [简写] 显示英文摘要

摘要： We present the first results from the COS-EDGES survey, targeting the kinematic connection between the ISM and multi-phase circumgalactic medium (CGM) in nine isolated, edge-on galaxies at z~0.2, each probed along its major axis by a background quasar at impact parameters of 13-38kpc. Using VLT/UVES and HST/COS quasar spectra, we analyse MgI, MgII, HI, CII, CIII, and OVI absorption relative to galaxy rotation curves from Keck/LRIS and Magellan/MagE spectra. We find that at lower $D/R_{vir}$ ($D/R_{vir}\leq 0.2$), over 80% of absorption in all ions lies on the side of systemic velocity matching disk rotation, and the optical-depth-weighted median velocity ($v_{abs}$) is consistent with the peak rotation speed. At higher $D/R_{vir}$ ($D/R_{vir} > 0.2$), the kinematics diverge by ionisation state: For low ionisation gas, the amount of co-rotating absorption remains >80%, yet $v_{abs}$ drops to 60% of the galaxy rotation speed. For high ionisation gas (OVI), only 60% of the absorption is consistent with co-rotation and $v_{abs}$ drops to 20% of the rotation speed. Furthermore, the velocity widths, corresponding to 50% of the total optical depth ($\Delta v_{50}$) for low ionisation gas is 1.8 times larger in the inner halo than at larger radii, while for CIII and OVI $\Delta v_{50}$ remains unchanged with distance. These results suggest a radially dependent CGM kinematic structure: the inner halo hosts cool, dynamically broad gas tightly coupled to disk rotation, whereas beyond 0.2$R_{vir}$, particularly traced by OVI and HI, the CGM shows weaker rotational alignment and lower velocity dispersion. Therefore, low-ionisation gas likely traces extended co-rotating gas, inflows and/or recycled accretion, while high-ionisation gas reflects a mixture of co-rotating, lagging, discrete collisionally ionised structures, indicating a kinematic stratification of the multi-phase CGM. [Abridged]