We present morphological and spectroscopic studies of the northwest rim of the supernova remnant RX J1713.7 - 3946 based on observations by the Chandra X-ray observatory .
We found a complex network of nonthermal ( synchrotron ) X-ray filaments , as well as a ’ void ’ type structure – a dim region of a circular shape – in the northwest rim .
It is remarkable that despite distinct brightness variations , the X-ray spectra everywhere in this region can be well fitted with a power-law model with photon index ranging \Gamma = 2.1–2.5 .
We briefly discuss some implications of these results and argue that the resolved X-ray features in the northwest rim may challenge the perceptions of the standard diffusive shock-acceleration models concerning the production , propagation and radiation of relativistic particles in supernova remnants .