发表机构
Queen’s University; Perimeter Institute for Theoretical Physics; University of Waterloo; McGill University; Trottier Space Institute; Arizona State University; University of British Columbia; National Research Council（女王大学; 理论物理前沿研究所; 滑铁卢大学; 麦吉尔大学; 特罗蒂尔太空研究所; 亚利桑那州立大学; 不列颠哥伦比亚大学; 国家研究委员会）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
CHORD通过无目标漂移扫描巡天扩展HI星系普查，从已知HI质量函数预测探测情况，预计5年巡天源计数大增，能将低质量HI星系普查推进到更低质量，还能探测高红移大质量富含气体巨星，增进对中性气体储库的理解。
AI 中文摘要
对已知具有中性氢（HI）质量范围（$10^5 \lesssim M_{\mathrm{HI}} \lesssim 10^{11} M_{\odot}$）的富含气体星系的总体研究，因需在大片天空区域进行高灵敏度、宽带巡天而受限。加拿大氢观测站和射电瞬变探测器（CHORD）是下一代射电望远镜，将通过在赤纬$+20^{\circ} < \delta < +80^{\circ}$进行无目标漂移扫描巡天，大幅扩展HI星系普查。我们从已知的HI质量函数（HIMF）得出巡天实现情况，预测在基准1年和5年CHORD巡天中的HI探测情况。预计5年巡天的源计数将比现有目录超出约一个数量级，同时我们也估计了射频干扰（RFI）和光谱源混淆的潜在影响。我们预测CHORD将把低质量HI星系普查推进到$M_{\mathrm{HI}} \sim 10^{5.5} M_{\odot}$，比之前达到的低一个数量级以上。在HIMF的高质量端，CHORD预计在$0.3 \lesssim z \lesssim 0.5$探测到约$10^{3}$个大质量富含气体巨星（$M_{\mathrm{HI}} \gtrsim 10^{10.5}\, M_{\odot}$），这将探索该群体相对于本地宇宙估计的演化。因此，CHORD HI巡天将增进我们对星系群体低质量和高质量极端情况下中性气体储库的理解。
英文摘要
Population studies of gas-rich galaxies across the full range of Neutral Hydrogen (HI) masses that galaxies are known to exhibit ($10^5 \lesssim M_{\mathrm{HI}} \lesssim 10^{11} M_{\odot}$) remain limited by the need to conduct high-sensitivity, wide-band surveys across significant sky areas. The Canadian Hydrogen Observatory and Radio-transient Detector (CHORD) is a next-generation radio telescope that will significantly expand the census of HI-galaxies to date from untargeted drift-scan surveys at declinations $+20^{\circ} < δ< +80^{\circ}$. We draw survey realizations from a known HI mass function (HIMF) to forecast HI detections in fiducial 1-year and 5-year CHORD surveys. The 5-year survey source counts is expected exceed currently available catalogs by roughly an order of magnitude, notwithstanding the potential impacts of radio frequency interference (RFI) and spectroscopic source confusion that we also estimate. We predict that CHORD will push the low-mass HI galaxy census to $M_{\mathrm{HI}} \sim 10^{5.5} M_{\odot}$, over an order of magnitude lower than has been previously achieved. At the high mass end of the HIMF, CHORD is expected to detect $\sim10^{3}$ massive gas-rich giants ($M_{\mathrm{HI}} \gtrsim 10^{10.5}\, M_{\odot}$) at $0.3 \lesssim z \lesssim 0.5$, which will explore the evolution of this population relative to local universe estimates. CHORD HI surveys will therefore improve our understanding of the neutral gas reservoirs at the low-mass and high-mass extremes of the galaxy population.
Comments16 Pages, 8 figures. Updated after reader feedback. Submitted to OJA
