标题： 对福尔纳克斯星系团的盲ATCA HI观测：HI检测的特性 显示英文标题

标题： A blind ATCA HI survey of the Fornax galaxy cluster: properties of the HI detections

摘要： We present the first interferometric blind HI survey of the Fornax galaxy cluster, which covers an area of 15 deg$^2$ out to the cluster $R_{vir}$. 该调查的分辨率为67''x95''，并且具有6.6公里$s^{-1}$，灵敏度为3$\sigma$的N(HI)~2x10$^{19}$ cm$^{-2}$以及MHI 2x10$^7$ M$_\odot$。 我们检测到了200个光谱确认的Fornax星系团成员中的16个星系。 这些检测覆盖了HI质量约3个数量级，从8x10$^6$到1.5x10$^{10}$ M$_\odot$。 它们避开了星系团天空和投影相空间中的中心、已达到动力学平衡的区域，表明它们是近期到达的，并且在Fornax中，HI在一次穿越时间（约2 Gyr）内被丢失。 这些星系中有一半表现出扰动的HI形态，包括一些不对称情况、尾部、HI和光学中心之间的偏移，以及一个HI盘被截断的情况，这表明它们已经在或前往Fornax的过程中发生过相互作用。 我们的HI检测结果比同一$M_\star$范围内的非星系团星系更缺乏HI，并且形成恒星的速率更低。 低质量星系在整个向星系团下落的过程中受到的影响更为强烈。 Fornax星系的MHI/$M_\star$比率与Virgo星系团中的比率相当。 在固定$M_\star$的情况下，我们的HI检测结果遵循非星系团中MHI与恒星形成速率之间的关系，我们认为这表明到目前为止，它们失去HI的时间尺度为$\gtrsim$1-2 Gyr。 在星系团内部，HI的去除可能进行得更快，这由一群未被探测到HI但被探测到H$_2$的形成恒星的星系得到证实。 基于ALMA的数据，我们发现H$_2$与HI质量比存在较大的离散性，其中几个星系表现出异常高的比值，这可能是由于HI去除速度更快所致。 我们识别出一个富含HI的可能相互作用星系子群，主要由NGC 1365主导，其中预处理很可能已经发生。 显示英文摘要

摘要： We present the first interferometric blind HI survey of the Fornax galaxy cluster, which covers an area of 15 deg$^2$ out to the cluster $R_{vir}$. The survey has a resolution of 67''x95'' and 6.6 km$s^{-1}$ with a 3$\sigma$ sensitivity of N(HI)~2x10$^{19}$ cm$^{-2}$ and MHI 2x10$^7$ M$_\odot$. We detect 16 galaxies out of 200 spectroscopically confirmed Fornax cluster members. The detections cover ~3 orders of magnitude in HI mass, from 8x10$^6$ to 1.5x10$^{10}$ M$_\odot$. They avoid the central, virialised region of the cluster both on the sky and in projected phase-space, showing that they are recent arrivals and that, in Fornax, HI is lost within a crossing time, ~2 Gyr. Half of these galaxies exhibit a disturbed HI morphology, including several cases of asymmetries, tails, offsets between HI and optical centres, and a case of a truncated HI disc suggesting that they have been interacting within or on their way to Fornax. Our HI detections are HI-poorer and form stars at a lower rate than non-cluster galaxies in the same $M_\star$ range. Low mass galaxies are more strongly affected throughout their infall towards the cluster. The MHI/$M_\star$ ratio of Fornax galaxies is comparable to that in the Virgo cluster. At fixed $M_\star$, our HI detections follow the non-cluster relation between MHI and the star formation rate, and we argue that this implies that so far they have lost their HI on a timescale $\gtrsim$1-2 Gyr. Deeper inside the cluster HI removal is likely to proceed faster, as confirmed by a population of HI-undetected but H$_2$-detected star-forming galaxies. Based on ALMA data, we find a large scatter in H$_2$-to-HI mass ratio, with several galaxies showing an unusually high ratio that is probably caused by faster HI removal. We identify an HI-rich subgroup of possible interacting galaxies dominated by NGC 1365, where pre-processing is likey to have taken place.