HI和OH盲吸收线搜索：使用ARTIP处理MALS和uGMRT的首次结果
Blind HI and OH absorption line search: first results with MALS and uGMRT processed using ARTIP
摘要：
我们目前的自动射电望远镜成像管道（ARTIP）的详细信息和结果的一个敏感的盲目搜索HI和OH吸收剂在$z<0.4$和$z<0.7$，分别。ARTIP是用Python 3.6编写的，广泛使用通用天文软件应用程序（CASA）工具和任务，旨在使地理分布的MeerKAT吸收线调查（MALS）团队能够协作处理大量的无线电干涉数据。我们将其应用于使用64碟MeerKAT射电望远镜和32 K通道模式的相关器获得的第一个MALS数据集。仅用40分钟的时间，我们就获得了PKS 1830 -211最灵敏的光谱，并表征了已知的HI（$z=0.19$）和OH（$z=0.89$）吸收剂。我们进一步展示了ARTIP的能力，以处理现实的观测情况下，将其应用到72个明亮的无线电源与升级后的巨型米波射电望远镜（UGMRT）观察到盲目搜索HI和OH吸收剂的样本。我们估计每单位红移的HI和OH吸收体的数量分别为$n_{21}(z\sim0.18)<$ 0.14和$n_{\rm OH}(z\sim0.40)<$ 0.12，并限制在大的影响参数（50 kpc $<ρ<$ 150 kpc）星系的冷气覆盖因子小于0.022。由于小的红移路径，对于HI的$Δz\sim$ 13，柱密度为$>5.4\times10^{19}$ cm $^{-2}$，巡天只探测了$ρ>30$ kpc的恒星形成星系的外围。具有预期$Δz\sim10^{3-4}$的MALS将克服这一限制，并对$0<z<1.5$上不同环境中星系的冷气分数提供严格的限制。
英文摘要：
We present details of the Automated Radio Telescope Imaging Pipeline (ARTIP) and results of a sensitive blind search for HI and OH absorbers at $z<0.4$ and $z<0.7$, respectively. ARTIP is written in Python 3.6, extensively uses the Common Astronomy Software Application (CASA) tools and tasks, and is designed to enable the geographically-distributed MeerKAT Absorption Line Survey (MALS) team to collaboratively process large volumes of radio interferometric data. We apply it to the first MALS dataset obtained using the 64-dish MeerKAT radio telescope and 32K channel mode of the correlator. With merely 40 minutes on target, we present the most sensitive spectrum of PKS1830-211 ever obtained and characterize the known HI ($z=0.19$) and OH ($z=0.89$) absorbers. We further demonstrate ARTIP's capabilities to handle realistic observing scenarios by applying it to a sample of 72 bright radio sources observed with the upgraded Giant Metrewave Radio Telescope (uGMRT) to blindly search for HI and OH absorbers. We estimate the numbers of HI and OH absorbers per unit redshift to be $n_{21}(z\sim0.18)<$0.14 and $n_{\rm OH}(z\sim0.40)<$0.12, respectively, and constrain the cold gas covering factor of galaxies at large impact parameters (50 kpc $<ρ<$ 150 kpc) to be less than 0.022. Due to the small redshift path, $Δz\sim$13 for HI with column density$>5.4\times10^{19}$ cm$^{-2}$, the survey has probed only the outskirts of star-forming galaxies at $ρ>30$ kpc. MALS with the expected $Δz\sim10^{3-4}$ will overcome this limitation and provide stringent constraints on the cold gas fraction of galaxies in diverse environments over $0<z<1.5$.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
