Interaction between the W51C Supernova Remnant and a Molecular Cloud. I. H I 21 Centimeter Line Observations
Interaction between the W51C Supernova Remnant and a Molecular Cloud. I. H I 21 Centimeter Line Observations
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DOI：
10.1086/303527
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发表时间：
1997-01
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影响因子：
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通讯作者：
B. Koo;D. moon
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作者：
B. Koo;D. moon
我们报告的结果，高分辨率H I 21厘米线观测的冲击星际气体在W51复杂。在vLSR +85和+180 km s-1之间探测到了冲击氢气体，这比银河系向这个方向（l = 49°）旋转所允许的最大速度（~60 km s-1）要大得多。氢气体沿着一个~20' × ~3'（或~35 pc × ~5 pc，距离6 kpc）的环状构造分布。速度结构表明，氢气体是一个膨胀，凹壳的一部分。通过与X射线/CO分布的比较，我们发现激波后的H I气体位于W51 C超新星遗迹（SNR）的X射线亮中心区与大分子云的交界面上。X射线，CO和H I发射之间的相关性强烈表明，由SNR驱动的冲击传播到分子云中。大量（>1200 M）的快速移动的H I气体表明该激波是一个快速的、辐射性的J型激波。VLA谱线剖面产生的最大视震速度为1070 km s-1。一个简单的模型，其中一个半球形的H I壳是从侧面扩展到一个圆柱形的云可以解释所观察到的形态和速度结构的H I气体。为投影校正的激波速度约为100 km s-1。我们推导出冲击参数，并讨论了SNR W51 C的影响。
We report the results of high-resolution H I 21 cm line observations of the shocked interstellar gas in the W51 complex. The shocked H I gas has been detected between vLSR ≃ +85 and +180 km s-1, which is much greater than the maximum velocity (~60 km s-1) permitted by the Galactic rotation toward this direction (l = 49°). The H I gas is distributed along a looplike filamentary structure of ~20' × ~3' size (or ~35 pc × ~5 pc at a distance of 6 kpc). The velocity structure indicates that the H I gas is a portion of an expanding, concave shell. By comparing with the X-ray/CO distributions, we have found that the shocked H I gas is located at an interface between the X-ray-bright central region of the W51C supernova remnant (SNR) and a large molecular cloud. The correlation between the X-ray, CO, and H I emissions strongly suggests that a shock driven by the SNR is propagating into the molecular cloud. The large amount (>1200 M☉) of fast-moving H I gas indicates that the shock is a fast, radiative, J-type shock. The VLA line profiles yield a maximum line-of-sight shock velocity of ≃70 km s-1. A simple model in which a hemispherical H I shell is expanding into a cylindrical cloud from the side could explain the observed morphology and velocity structure of the H I gas. The shock velocity corrected for the projection is ~100 km s-1. We derive the shock parameters and discuss the implications for the SNR W51C.