We report on results of Chandra X-ray observations of the southwestern part of the supernova remnant (SNR) RX J1713.7−3946. We measure proper motions of two X-ray bright blobs, named Blobs A and B, in regions presumably corresponding to the forward shock of the SNR. The measured velocities are 3800 ± 100 km s −1 and 2300 ± 200 km s −1 for Blobs A and B, respectively. Since a dense molecular clump is located close to Blob B, its slower velocity is attributed to shock deceleration as a result of a shock–cloud interaction. This result provides solid evidence that the forward shock of RX J1713.7−3946 is indeed colliding with dense gas discovered through radio observations reported in the literature. The locations and velocity differences of the two blobs lead to an estimate that the shock encountered with the dense gas ∼100 yr ago. The shock velocities, together with cutoff energies of the synchrotron X-ray spectra of the blobs, indicate that particle acceleratio...

中文翻译：

---

钱德拉X射线观测证明RX J1713.7–3946西南边缘的激波-云相互作用

我们报告了对超新星遗迹（SNR）RX J1713.7-3946西南部分的钱德拉X射线观察结果。我们在可能对应于SNR的正向震荡的区域中测量了两个X射线明亮的Blob（分别称为Blob A和B）的适当运动。斑点A和B的测得速度分别为3800±100 km s -1和2300±200 km s -1。由于稠密的分子团块靠近Blob B，因此它的较慢速度归因于冲击云相互作用引起的冲击减速。该结果提供了有力的证据，表明RX J1713.7-3946的前向冲击确实与文献中报道的通过无线电观测发现的稠密气体发生了碰撞。两个斑点的位置和速度差异导致估计到大约100年以前在浓密气体中遇到了震动。