论文标题
中央质量浓度对磁盘星系中棒形成的影响
Effects of the Central Mass Concentration on Bar Formation in Disk Galaxies
论文作者
论文摘要
尽管条形在磁盘星系中很常见，但它们的形成条件尚不清楚。我们使用$ n $ - 体模拟来研究棒状星系中的棒形成和进化，这些星系由恒星磁盘，经典的凸起和黑暗的光环组成。我们考虑了24种与银河系相似的星系模型，但在经典凸起和光晕浓度的质量和紧凑性上有所不同。 We find that the bar formation requires $(Q_{T,\text{min}}/1.2)^2 + (\text{CMC}/0.05)^2\lesssim 1$, where $Q_{T,\text{min}}$ and CMC refers to the minimum value of the Toomre stability parameter and the central mass concentration, respectively.条形趋于较强，更长，并且在星系中旋转较慢，较小且紧凑的凸起和光环较小。我们的模型中形成的所有条形都对应于慢速条。凸起质量为$ \ sim10 $的型号 - $ 20 $ \％的集中光环下的磁盘产生类似于乳白色棒的条。我们讨论了与先前研究建议的其他条形形成标准有关的发现。
While bars are common in disk galaxies, their formation conditions are not well understood. We use $N$-body simulations to study bar formation and evolution in isolated galaxies consisting of a stellar disk, a classical bulge, and a dark halo. We consider 24 galaxy models that are similar to the Milky Way but differ in the mass and compactness of the classical bulge and halo concentration. We find that the bar formation requires $(Q_{T,\text{min}}/1.2)^2 + (\text{CMC}/0.05)^2\lesssim 1$, where $Q_{T,\text{min}}$ and CMC refers to the minimum value of the Toomre stability parameter and the central mass concentration, respectively. Bars tend to be stronger, longer, and rotate slower in galaxies with a less massive and less compact bulge and halo. All bars formed in our models correspond to slow bars. A model with the bulge mass of $\sim10$--$20$\% of the disk under a concentrated halo produces a bar similar to the Milky-Way bar. We discuss our findings in relation to other bar formation criteria suggested by previous studies.
