Multi-filament gas inflows fuelling young star-forming galaxies
Multi-filament gas inflows fuelling young star-forming galaxies
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DOI：
10.1038/s41550-019-0791-2
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发表时间：
2019-07
期刊：
影响因子：
14.1
通讯作者：
D. C. Martin;D. O’Sullivan;M. Matuszewski;E. Hamden;A. Dekel;S. Lapiner;P. Morrissey;J. Neill;S. Cantalupo;J. Prochaska;C. Steidel;R. Trainor;A. Moore;D. Ceverino;J. Primack;L. Rizzi
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文献类型：
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作者：
D. C. Martin;D. O’Sullivan;M. Matuszewski;E. Hamden;A. Dekel;S. Lapiner;P. Morrissey;J. Neill;S. Cantalupo;J. Prochaska;C. Steidel;R. Trainor;A. Moore;D. Ceverino;J. Primack;L. Rizzi
理论表明，有两种主要的吸积模式，通过这种模式，暗物质晕获得气体以形成星系并为星系提供燃料：热流和冷流吸积。在冷流吸积中，气体流沿着宇宙网的细丝到达光环的中心，从而有效地输送恒星形成的燃料。最近，两个类星体照明的HiLyman α（Lyα）发射物体被报道具有冷旋转结构的特性。然而，可用的空间和光谱分辨率不足以约束与连接细丝相关的径向流动。有了凯克宇宙网络成像仪（KCWI），我们现在有了八倍的空间分辨率，可以检测到这些螺旋流动。为了检测这些流入，我们介绍了一套模型，纳入纬向径向流，展示了它们的性能的数值模拟，表现出冷流吸积，并表明，他们是一个很好的匹配KCWI速度图的两个Lyα发射体周围观察到的高红移类星体。这些多丝流入模型在运动学上隔离了对应于扩展的非连续排放的径向流入区域。导出的气体流量和流入路径足以为推断的中央星系恒星形成速率和角动量提供燃料。因此，我们的运动学发射图提供了强有力的证据，表明来自宇宙网的气体流入正在星星形成的高峰期建造星系。
Theory suggests that there are two primary modes of accretion through which dark-matter halos acquire the gas to form and fuel galaxies: hot- and cold-flow accretion. In cold-flow accretion, gas streams along cosmic web filaments to the centre of the halo, allowing for the efficient delivery of star-forming fuel. Recently, two quasar-illuminated HiLyman ɑ (Lyα)-emitting objects were reported to have properties of cold, rotating structures,. However, the spatial and spectral resolution available was insufficient to constrain the radial flows associated with connecting filaments. With the Keck Cosmic Web Imager (KCWI), we now have eight times the spatial resolution, permitting the detection of these inspiralling flows. To detect these inflows, we introduce a suite of models that incorporate zonal radial flows, demonstrate their performance on a numerical simulation that exhibits cold-flow accretion, and show that they are an excellent match to KCWI velocity maps of two Lyα emitters observed around high-redshift quasars. These multi-filament inflow models kinematically isolate zones of radial inflow that correspond to extended filamentary emission. The derived gas flux and inflow path is sufficient to fuel the inferred central galaxy star-formation rate and angular momentum. Thus, our kinematic emission maps provide strong evidence that the inflow of gas from the cosmic web is building galaxies at the peak of star formation.