标题： JCMT近邻星系遗产巡天——XI. ——近邻漩涡星系原子和分子气体径向分布的环境变化 显示英文标题

标题： The JCMT Nearby Galaxies Legacy Survey -- XI. -- Environmental Variations in the Atomic and Molecular Gas Radial Profiles of Nearby Spiral Galaxies

摘要： 我们分析了来自近邻星系遗产巡天（NGLS）的43个通过詹姆斯·克拉克·麦克斯韦望远镜（JCMT）CO $J=3-2$ 和/或甚大阵列（VLA）HI 成图观测解析的HI流量选择的旋涡星系样本的径向分布。将处女座星系群和非处女座星系群进行比较后，我们确认处女座样本中的HI盘是截断的，即使对于这些相对富含HI的星系也是如此。另一方面，在处女座星系的中心附近，H$_{2}$ 的分布得到了增强，导致更高的H$_{2}$ 与HI的比例以及更陡峭的H$_{2}$ 和总气体径向分布。这可能是由于星团环境中适度的冲击压力剥离效应造成的，这种效应会优先去除外围的低密度气体，同时增强中心附近的高密度气体。结合H$\alpha$ 星形成率数据，我们发现对于两个样本来说，恒星形成效率（SFR/H$_{2}$）随半径变化相对恒定，但处女座星系的恒星形成效率比非处女座星系低$\sim40\%$。 显示英文摘要

摘要： We present an analysis of the radial profiles of a sample of 43 HI-flux selected spiral galaxies from the Nearby Galaxies Legacy Survey (NGLS) with resolved James Clerk Maxwell Telescope (JCMT) CO $J=3-2$ and/or Very Large Array (VLA) HI maps. Comparing the Virgo and non-Virgo populations, we confirm that the HI disks are truncated in the Virgo sample, even for these relatively HI-rich galaxies. On the other hand, the H$_{2}$ distribution is enhanced for Virgo galaxies near their centres, resulting in higher H$_{2}$ to HI ratios and steeper H$_{2}$ and total gas radial profiles. This is likely due to the effects of moderate ram pressure stripping in the cluster environment, which would preferentially remove low density gas in the outskirts while enhancing higher density gas near the centre. Combined with H$\alpha$ star formation rate data, we find that the star formation efficiency (SFR/H$_{2}$) is relatively constant with radius for both samples, but Virgo galaxies have a $\sim40\%$ lower star formation efficiency than non-Virgo galaxies.