Shock–Cloud Interaction in the Southwestern Rim of RX J1713.7–3946 Evidenced by Chandra X-Ray Observations
Shock–Cloud Interaction in the Southwestern Rim of RX J1713.7–3946 Evidenced by Chandra X-Ray Observations
复制标题
钱德拉 X 射线观测证实 RX J1713.7–3946 西南缘的激波与云相互作用
作者：
Takaaki Tanaka;H. Uchida;H. Sano;T. Tsuru
我们报告了钱德拉X射线观测超新星遗迹（SNR）RX J1713.7−3946西南部的结果。我们测量自行的两个X射线明亮的斑点，名为斑点A和B，在该地区大概对应的前向冲击的SNR。对于斑点A和B，测得的速度分别为3800 ± 100 km s-1和2300 ± 200 km s-1。由于一个致密的分子团位于靠近BloB B的位置，其较慢的速度归因于激波-云相互作用的激波减速。这一结果提供了坚实的证据，证明RX J1713.7−3946的前向激波确实与文献中报道的射电观测发现的稠密气体发生了碰撞。这两个团块的位置和速度差异导致了一种估计，即冲击波在100年前与致密气体相遇。冲击波速度以及斑点同步加速器X射线光谱的截止能量表明，这些区域中的粒子加速接近玻姆极限。特别是BloB B，几乎达到了极限，以尽可能快的速度加速粒子。我们讨论了激波-云相互作用对粒子加速效率的可能影响。
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 acceleration in these regions is close to the Bohm limit. Blob B, in particular, is almost at the limit, accelerating particles at the fastest possible rate. We discuss possible influence of the shock–cloud interaction on the efficiency of particle acceleration.