局域宇宙中星系棒演化的运动学线索：为什么旋转最快的棒旋转最慢
Kinematic clues to bar evolution for galaxies in the local universe: why the fastest rotating bars are rotating most slowly
摘要：
我们利用本机宇宙中68个棒旋星系的斯皮策图像对棒旋星系的长度和强度进行了系统的测量。我们结合这些与棒的共转半径的精确测定，从我们以前的研究，其中使用的相位变化从径向流入径向流出的气体在共转，基于高分辨率的二维速度场的Hα所采取的法布里-珀罗光谱仪。在给出导出的棒参数的直方图之后，我们研究了它们对星系形态类型和宿主星系的总恒星质量的依赖性，然后产生一组参数图。这些包括棒图案速度与棒长度的关系、用外盘的特征图案速度归一化的图案速度与棒强度的关系、以及归一化的图案速度与R（共转半径与棒长度的比率）的关系。为了给我们的解释提供指导，我们使用了最近发表的模拟，包括盘和暗物质晕成分。我们最引人注目的结论是，R < 1.4的值的酒吧，以前被认为是动态快速旋转，可以是最慢的旋转无论是在绝对值，当他们的模式速度归一化。模拟证实，这是因为当棒被制动时，它们可以比正转半径的向外漂移更快地增长。我们的结论是，暗物质晕确实减缓了Gyr时间尺度上棒的旋转。
英文摘要：
We have used Spitzer images of a sample of 68 barred spiral galaxies in the local universe to make systematic measurements of bar length and bar strength. We combine these with precise determinations of the corotation radii associated with the bars, taken from our previous study which used the phase change from radial inflow to radial outflow of gas at corotation, based on high resolution two-dimensional velocity fields in Hα taken with a Fabry-Pérot spectrometer. After presenting the histograms of the derived bar parameters, we study their dependence on the galaxy morphological type and on the total stellar mass of the host galaxy, and then produce a set of parametric plots. These include the bar pattern speed versus bar length, the pattern speed normalized with the characteristic pattern speed of the outer disk versus the bar strength, and the normalized pattern speed versus R, the ratio of corotation radius to bar length. To provide guide-lines for our interpretation we used a recently published simulations, including disk and dark matter halo components. Our most striking conclusion is that bars with values of R < 1.4, previously considered dynamically fast rotators, can be among the slowest rotators both in absolute terms and when their pattern speeds are normalized. The simulations confirm that this is because as the bars are braked they can grow longer more quickly than the outward drift of the corotation radius. We conclude that dark matter halos have indeed slowed down the rotation of bars on Gyr timescales.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
