论文标题
Illustristng中偏斜的银河磁盘
Lopsided galactic disks in IllustrisTNG
论文作者
论文摘要
附近的大部分晚期星系大部分被误导。我们研究了从插图TNG100模拟的最后一个快照中选择的良好分辨的摩擦星系中恒星成分的不对称性，这些星系的平坦度和旋转支持。在1912年的磁盘中，我们通过（1-2）恒星半质量半径在（1-2）个恒星组成的M = 1傅立叶模式方面识别161个对象，并使用三个代表性的示例描述其性质。 M = 1模式的轮廓通常随半径增加而增加，并且相应的相位在不对称区域是恒定的，表示全局变形。随着时间的流逝，随着时间的流逝，我们发现它们的历史相当顺利，不对称的发生也相当新。最近只有大约1/3的磁盘经历了任何强烈的相互作用，这可能导致其形状的变形：24％受到更大的物体影响，而9％的人进行了富含气体的合并。尽管如此，大多数偏斜的磁盘仍显示出其最近的恒星形成率显着提高。因此，尽管气体和恒星中的畸变并未密切相关，但偏斜盘形成的最常见机制似乎是不对称的恒星形成。这张照片得到了以下发现的支持：与剩余的磁盘相比，偏斜的人口平均含有更多的气体，恒星形成速率更高，金属性较低和蓝色。这些相关性与在实际星系中看到的相关性相似，即使模拟的磁盘的比例（8％）远低于观测值（30％）。观察到的不对称和条形存在之间观察到的相关性也没有再现。这些差异可能是由于插图模拟的过度解决或分辨率不足所致。
A significant fraction of nearby late-type galaxies are lopsided. We study the asymmetry of the stellar component in a sample of well-resolved disky galaxies selected from the last snapshot of the Illustris TNG100 simulation based on their flatness and rotational support. Among 1912 disks, we identify 161 objects with significant asymmetry in terms of the m=1 Fourier mode of the stellar component within (1-2) stellar half-mass radii and describe their properties using three representative examples. The profiles of the m=1 mode typically increase with radius, and the corresponding phase is constant in the asymmetric region, signifying a global distortion. Following the evolution of the lopsided disks over time, we find that their history is rather uneventful and the occurrence of the asymmetry is fairly recent. Only about 1/3 of the lopsided disks experienced any strong interaction recently that could have led to the distortion of their shape: 24% were affected by a more massive object and 9% underwent a gas-rich merger. Still, a majority of lopsided disks show a significant increase in their recent star formation rate. The most frequent mechanism for the formation of lopsided disks thus seems to be asymmetric star formation probably related to gas accretion, although the distortions in the gas and stars are not strongly correlated. This picture is supported by the finding that the lopsided population on average contains more gas, has higher star formation rate, lower metallicity and bluer color than the remaining disks. These correlations are similar to those seen in real galaxies, even though the fraction of simulated lopsided disks (8%) is much lower than in observations (30%). The observed correlation between the presence of the asymmetry and a bar is not reproduced either. These discrepancies may be due to overquenching or insufficient resolution of IllustrisTNG simulations.
