标题： WALLABY先导调查：长蛇座星系团中星系HI气体的ram压力剥离多样性 显示英文标题

标题： WALLABY Pilot Survey: the diversity of ram pressure stripping of the galactic HI gas in the Hydra Cluster

摘要： 本研究使用了ASKAP望远镜的WALLABY先导调查中的HI图像数据，覆盖了Hydra星系团至2.5$r_{200}$的范围。 我们展示了Hydra中检测到HI的星系的投影相空间分布，并确定在$1.25r_{200}$范围内几乎三分之二的星系可能正处于ram压力剥离的早期阶段。 其中超过一半的星系可能仅被弱剥离，可剥离HI（即银河恢复力低于盘中ram压力）的质量分数（相对于总HI质量）在90%以下均匀分布。 因此，预计在这些系统中当前可剥离的HI部分被剥离后，HI质量只会减少几个0.1 dex。 对WALLABY观测中空间分辨的星系子集进行更详细的观察显示，虽然通常需要不到200 Myr的时间才能去除当前可剥离的HI部分，但可能需要超过600 Myr才能显著改变总HI质量。 我们的结果为理解星系团中HI耗尽和恒星形成抑制的不同速率提供了新的线索。 显示英文摘要

摘要： This study uses HI image data from the WALLABY pilot survey with the ASKAP telescope, covering the Hydra cluster out to 2.5$r_{200}$. We present the projected phase-space distribution of HI-detected galaxies in Hydra, and identify that nearly two thirds of the galaxies within $1.25r_{200}$ may be in the early stages of ram pressure stripping. More than half of these may be only weakly stripped, with the ratio of strippable HI (i.e., where the galactic restoring force is lower than the ram pressure in the disk) mass fraction (over total HI mass) distributed uniformly below 90%. Consequently, the HI mass is expected to decrease by only a few 0.1 dex after the currently strippable portion of HI in these systems has been stripped. A more detailed look at the subset of galaxies that are spatially resolved by WALLABY observations shows that, while it typically takes less than 200 Myr for ram pressure stripping to remove the currently strippable portion of HI, it may take more than 600 Myr to significantly change the total HI mass. Our results provide new clues to understanding the different rates of HI depletion and star formation quenching in cluster galaxies.