How do different spiral arm models impact the ISM and GMC population?
How do different spiral arm models impact the ISM and GMC population?
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DOI：
10.1093/mnras/staa2242
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发表时间：
2020-07
影响因子：
4.8
通讯作者：
A. Pettitt;C. Dobbs;J. Baba;D. Colombo;A. Duarte-Cabral;F. Egusa;A. Habe
中科院分区：
文献类型：
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作者：
A. Pettitt;C. Dobbs;J. Baba;D. Colombo;A. Duarte-Cabral;F. Egusa;A. Habe
盘状星系中星系旋臂的性质仍然难以捉摸。不管螺旋模型是什么，旋臂在塑造恒星形成的星际介质（ISM）中都扮演着重要的角色。因此，不同的臂模型可能导致ISM结构和分子云性质的差异。在这项研究中，我们提出了银河盘受到不同性质的旋臂扰动的模拟。我们发现，在不同的大设计螺旋之间，云团数量或气体运动学变化的差异很小，这表明云尺度上的ISM很少关心旋臂来自哪里。然而，我们确实看到了臂间/臂质谱的差异，以及云特性分布尾部的微小差异（以及恒星/气体速度色散的径向变化）。这些特征可以归因于不同螺旋模式之间模式速度的径向依赖性的差异，并且可以作为观测研究中螺旋结构性质的度量。
The nature of galactic spiral arms in disc galaxies remains elusive. Regardless of the spiral model, arms are expected to play a role in sculpting the star-forming interstellar medium (ISM). As such, different arm models may result in differences in the structure of the ISM and molecular cloud properties. In this study, we present simulations of galactic discs subject to spiral arm perturbations of different natures. We find very little difference in how the cloud population or gas kinematics vary between the different grand design spirals, indicating that the ISM on cloud scales cares little about where spiral arms come from. We do, however, see a difference in the interarm/arm mass spectra, and minor differences in tails of the distributions of cloud properties (as well as radial variations in the stellar/gaseous velocity dispersions). These features can be attributed to differences in the radial dependence of the pattern speeds between the different spiral models, and could act as a metric of the nature of spiral structure in observational studies.