We present maps in several molecular emission lines of a 1 square-degree region covering the W40 and Serpens South molecular clouds belonging to the Aquila Rift complex. The observations were made with the 45 m telescope at the Nobeyama Radio Observatory. We found that the $^{12}$CO and $^{13}$CO emission lines consist of several velocity components with different spatial distributions. The component that forms the main cloud of W40 and Serpens South, which we call the "main component", has a velocity of $V_{\rm LSR}\simeq 7$ km s$^{-1}$. There is another significant component at $V_{\rm LSR}\simeq 40$ km s$^{-1}$, which we call the "40 km s$^{-1}$ component". The latter component is mainly distributed around two young clusters: W40 and Serpens South. Moreover, the two components look spatially anti-correlated. Such spatial configuration suggests that the star formation in W40 and Serpens South was induced by the collision of the two components. We also discuss a possibility that the 40 km s$^{-1}$ component consists of gas swept up by superbubbles created by SNRs and stellar winds from the Scorpius-Centaurus Association.

中文翻译：

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Aquila Rift 云结构和动力学的详细分析

我们在覆盖 W40 和 Serpens South 分子云的 1 平方度区域的几个分子发射线中呈现地图，这些分子云属于 Aquila Rift 复合体。观测是使用野边山射电天文台的 45 m 望远镜进行的。我们发现 $^{12}$CO 和 $^{13}$CO 排放线由几个具有不同空间分布的速度分量组成。形成 W40 和 Serpens South 主云的组件，我们称之为“主组件”，速度为 $V_{\rm LSR}\simeq 7$ km s$^{-1}$。在 $V_{\rm LSR}\simeq 40$ km s$^{-1}$ 处还有另一个重要分量，我们称之为“40 km s$^{-1}$ 分量”。后一部分主要分布在两个年轻的星团周围：W40 和 Serpens South。此外，这两个分量在空间上看起来是反相关的。这种空间配置表明 W40 和 Serpens South 中的恒星形成是由两种成分的碰撞引起的。我们还讨论了 40 公里 s$^{-1}$ 成分由 SNR 产生的超级气泡和来自 Scorpius-Centaurus Association 的恒星风扫过的气体组成的可能性。