arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1009.0403astro-ph.CO
收藏

NGC 1300动力学:III。轨道分析

NGC 1300 Dynamics: III. Orbital analysis

P. A. Patsis, C. Kalapotharakos, P. Grosbol

摘要:

我们提出了四个响应模型的轨道分析,成功地再现NGC 1300的形态特征。它们中的两个假设平面(2D)几何形状,分别具有$Ω_p$ =22和16 \ksk。其他两个假设一个圆柱形(厚)盘,并以与2D模型相同的模式速度旋转。这些响应模型最成功地再现了NGC 1300的主要形态特征,在大量的模型中,在以前的研究中变得很明显。我们的主要结果是发现了三种新的动力学机制,可以支持棒螺旋大设计系统中的结构。这些机制的特征情况下,这些动态现象发生。它们首先是指几乎完全由混沌轨道支撑的一个强杆,ansae型,然后是指由混沌轨道支撑的螺旋,对于一定数量的模式旋转遵循n:1(n= 7,8)的形态,最后是指由L $_{4,5}$周围的轨道和具有相同雅可比常数的粘性混沌轨道的组合支撑的螺旋臂。当我们改变一般模型的参数时,在我们研究的大部分情况下,我们都遇到了这些动力学现象,而没有以某种方式强迫它们出现。这表明它们可能是许多棒旋星系观测到的形态的原因。比较我们的响应模型,我们发现NGC 130 0的形态是最好的描述了一个厚盘模型的酒吧区和一个二维盘模型的螺旋,与两个组件旋转相同的模式速度$Ω_p$ =16 \ksk!在这种情况下,整个结构都包含在系统的共转中。杆主要由规则轨道支撑,而螺旋由混沌轨道支撑。

英文摘要:

We present the orbital analysis of four response models, that succeed in reproducing morphological features of NGC 1300. Two of them assume a planar (2D) geometry with $Ω_p$=22 and 16 \ksk respectively. The two others assume a cylindrical (thick) disc and rotate with the same pattern speeds as the 2D models. These response models reproduce most successfully main morphological features of NGC 1300 among a large number of models, as became evident in a previous study. Our main result is the discovery of three new dynamical mechanisms that can support structures in a barred-spiral grand design system. These mechanisms are presented in characteristic cases, where these dynamical phenomena take place. They refer firstly to the support of a strong bar, of ansae type, almost solely by chaotic orbits, then to the support of spirals by chaotic orbits that for a certain number of pat tern revolutions follow an n:1 (n=7,8) morphology, and finally to the support of spiral arms by a combination of orbits trapped around L$_{4,5}$ and sticky chaotic orbits with the same Jacobi constant. We have encountered these dynamical phenomena in a large fraction of the cases we studied as we varied the parameters of our general models, without forcing in some way their appearance. This suggests that they could be responsible for the observed morphologies of many barred-spiral galaxies. Comparing our response models among themselves we find that the NGC 130 0 morphology is best described by a thick disc model for the bar region and a 2D disc model for the spirals, with both components rotating with the same pattern speed $Ω_p$=16 \ksk !. In such a case, the whole structure is included inside the corotation of the system. The bar is supported mainly by regular orbits, while the spirals are supported by chaotic orbits.

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。

↑