论文标题
钢筋中恒星形成效率的统计研究：恒星形成是否抑制了富含气体的棒？
Statistical Study of the Star Formation Efficiency in Bars: Is Star Formation Suppressed in Gas-Rich Bars?
论文作者
论文摘要
最近有人讨论了恒星形成效率（SFE）对银河系结构的依赖性，尤其是酒吧区域的SFE是否低于其他地区的SFE。我们报告了附近18个气体巨大的恒星形成星系的SFE，上面有一个明显的杆大轴（$ \ geqq 75^{\ prime \ prime} $）。我们首次通过区分中心，棒端和条形区域来统计测量SFE。分子气体表面密度来自档案CO（1-0）和/或CO（2-1）数据，通过假设CO-TO-H $ _2 $转换因子（$α_ {\ rm co} $），而星形构造速率表面密度源自Far-OultravioLet和Mid-Mid-Mid-Mid-Mid-Frared infrared in-Frared infrared insensensient。角分辨率为$ 15^{\ prime \ prime} $，对应于$ 0.3-1.8〜 \ rm kpc $。我们发现，栏中的SFE与磁盘中的SFE的比率系统在系统上低于Unity（通常为$ 0.6-0.8 $），这意味着棒中的恒星形成系统地被系统地抑制。我们的结果与最近的类似统计研究不一致，这些研究报告说SFE往往与银河系结构无关。这种不一致可以归因于条形区域的定义，空间分辨率，$α_ {\ rm co} $和样品星系的差异。此外，我们发现SFE与CO频谱的速度宽度之间存在负相关性，这与以下观点一致：大型动态效应（例如，强烈的剪切，大剪切和快速云的碰撞）导致了棒的非圆形碰撞，从而导致低SFE。
The dependence of star formation efficiency (SFE) on galactic structures, especially whether the SFE in the bar region is lower than those in the other regions, has recently been debated. We report the SFEs of 18 nearby gas-rich massive star-forming barred galaxies with a large apparent bar major axis ($\geqq 75^{\prime\prime}$). We statistically measure the SFE by distinguishing the center, bar-end, and bar regions for the first time. The molecular gas surface density is derived from archival CO(1-0) and/or CO(2-1) data by assuming a constant CO-to-H$_2$ conversion factor ($α_{\rm CO}$), and the star formation rate surface density is derived from a linear combination of far-ultraviolet and mid-infrared intensities. The angular resolution is $15^{\prime\prime}$, which corresponds to $0.3 - 1.8~\rm kpc$. We find that the ratio of the SFE in the bar to that in the disk was systematically lower than unity (typically $0.6-0.8$), which means that the star formation in the bar is systematically suppressed. Our results are inconsistent with similar recent statistical studies that reported that SFE tends to be independent of galactic structures. This inconsistency can be attributed to the differences in the definition of the bar region, spatial resolution, $α_{\rm CO}$, and sample galaxies. Furthermore, we find a negative correlation between SFE and velocity width of the CO spectrum, which is consistent with the idea that the large dynamical effects, such as strong shocks, large shear, and fast cloud-cloud collisions caused by the noncircular motion of the bar, result in a low SFE.
