标题： z ~ 4.5星系的多样化样本中观察到的常规旋转和低湍流 显示英文标题

标题： Regular rotation and low turbulence in a diverse sample of z ~ 4.5 galaxies observed with ALMA

摘要： 在红移$\geq$处发现具有规则旋转盘的星系，这对星系形成模型构成了一个令人困惑的挑战，因为这些模型通常预测早期宇宙中由于气体吸积、合并和高效的反馈作用会导致混乱的气体动力学。 在本研究中，我们研究了五个多分辨率星系在 z$\sim$4.5 时用ALMA观测到的[CII]158$\mu$m发射线中的动力学特性。 样本是多样的：AzTEC1（超星系星暴星系），BRI1335-0417（超星系星暴和类星体宿主星系），J081740（正常恒星形成星系）和SGP38326（一组中的两个超星系星暴星系）。 这五个星系表现出速度梯度，但其中四个被发现是旋转盘，而剩下的AzTEC1可能是一个合并体。 我们使用3DBAROLO研究了盘状结构的气体动力学，发现它们的最大旋转速度在198到562公里/秒之间，而盘状结构上的气体速度弥散度平均在49到75公里/秒之间。 旋转曲线通常是平坦的，这些星系有序运动与随机运动的比率（V/$\sigma$）在2.7到9.8之间。 我们提出了CANNUBI，一种用于在建模动力学之前拟合三维发射线观测中旋转盘几何结构的算法，通过该算法我们发现这些盘的厚度可能在1千秒差距量级。 这项研究表明，在各种类型的星系中都存在早期盘状结构的形成，其旋转运动明显占主导地位，相对于湍流运动而言。 显示英文摘要

摘要： The discovery of galaxies with regularly rotating discs at redshifts $\geq$ has been a puzzling challenge to galaxy formation models that tend to predict chaotic gas kinematics in the early Universe as a consequence of gas accretion, mergers and efficient feedback. In this work, we investigated the kinematics of five highly resolved galaxies at z $\sim$ 4.5 observed with ALMA in the [CII] 158 $\mu$m emission line. The sample is diverse: AzTEC1 (starburst galaxy), BRI1335-0417 (starburst and quasar host galaxy), J081740 (normal star-forming galaxy) and SGP38326 (two starburst galaxies in a group). The five galaxies show velocity gradients, but four were found to be rotating discs while the remaining, AzTEC1, is likely a merger. We studied the gas kinematics of the discs using 3DBAROLO and found that they rotate with maximum rotation velocities between 198 and 562 km/s while the gas velocity dispersions, averaged across the discs, are between 49 and 75 km/s. The rotation curves are generally flat and the galaxies have ratios of ordered-to-random motion (V/$\sigma$) between 2.7 and 9.8. We present CANNUBI, an algorithm for fitting the disc geometry of rotating discs in 3D emission-line observations prior to modelling the kinematics, with which we find indications that these discs may have thicknesses of the order of 1 kpc. This study shows that early disc formation with a clear dominance of rotation with respect to turbulent motions is present across a variety of galaxy types.