论文标题
快速无线电爆发的宿主星系中分子气的多种特性
Diverse Properties of Molecular Gas in the Host Galaxies of Fast Radio Bursts
论文作者
论文摘要
我们报告了从与Atacama大毫米/亚毫升阵列获得的六个快速无线电爆发（FRB）样本中的分子气体的特性（FRBS 20180924B，20190102C和20190711a），并在一个未检测的结果中检测到了dwarf calaxy and dwarfbalaxy ins and dwarfbalaxy ins and dwarfbalax111101101102a （FRB20200120E）和银河系（FRB20200428A）。 CO观察结果分别在FRB20190190102C和FRB20190711a的宿主中检测到FRB20180924B宿主中的CO（3-2）发射。派生的分子气体和3 $σ$上限为$（2.4 \ pm 0.2）\ times 10^9 $ $ m _ {\ odot} $，$ <3.8 \ times 10^8 $ $ $ $ $ m _ {\ odot} $ FRB20190102C和FRB20190711A。我们发现样品中的分子气体特性（气体质量，气体耗竭时间和气体分数）的多样性。与其他恒星形成星系相比，FRB20180924B宿主是气体富含气体（较大的分子气体分数），而FRB20190102C和FRB20200120E的宿主在其恒星质量和星形构型的情况下是较短的耗尽时间。我们的发现表明，FRB来自多个祖细胞或单个祖细胞，这些祖细胞可能存在于广泛的星系环境中。统计分析表明，FRB宿主与局部星形星系之间的分子气体分数分布有显着差异。但是，当排除离群值（FRB20200120E主机）时，差异并不是很大，并且需要使用较大样本的分析。
We report the properties of molecular gas in a sample of six host galaxies of fast radio bursts (FRBs) obtained from CO observations with the Atacama Large Millimeter/submillimeter Array (FRBs 20180924B, 20190102C, and 20190711A) and results of one non-detection in a dwarf galaxy (FRB20121102A) and two events detected in M81 (FRB20200120E) and the Milky Way (FRB20200428A). The CO observations resulted in the detection of CO(3-2) emission in the FRB20180924B host and non-detections of CO(3-2) and CO(2-1) emission in the hosts of FRB20190102C and FRB20190711A, respectively. The derived molecular gas mass and 3$σ$ upper limit is $(2.4 \pm 0.2) \times 10^9$ $M_{\odot}$, $<3.8 \times 10^8$ $M_{\odot}$, and $<6.7 \times 10^9$ $M_{\odot}$ for the hosts of FRB20180924B, FRB20190102C, and FRB20190711A, respectively. We found diversity in molecular gas properties (gas mass, gas depletion time, and gas fraction to stellar mass) in the sample. Compared to other star-forming galaxies, the FRB20180924B host is gas-rich (the larger molecular gas fraction), and the hosts of FRB20190102C and FRB20200120E are gas-poor with a shorter depletion time for their stellar mass and star-formation rate. Our findings suggest that FRBs arise from multiple progenitors or single progenitors that can exist in a wide range of galaxy environments. Statistical analysis shows a significant difference in the distribution of molecular gas fraction between the FRB hosts and local star-forming galaxies. However, the difference is not substantial when an outlier, the FRB20200120E host, is excluded, and analysis with a larger sample is needed.
