Spectral Properties of nonthermal X-ray emission from the shell-type SNR RX1713.7-3946 revealed y XMM-Newton

We present the results of our morphological and spectral study of properties of the supernova remnant RX J1713.7-3946 based on data obtained with XMM-Newton. Highly inhomogeneous structures, such as the bright spots, filaments and dark voids, noted by Uchiyama et al. (2003), appear in the entire bright western portion of the shell. In addition two narrow rims are found which run parallel to each other from north to south in the western part of the remnant. No complex structures are seen in the interior region of the remnant. The X-ray spectra everywhere can be well represented with a power-law function of photon index ranging within Gamma = 2.0-2.8. A clear difference of spectra between the central dim region and the bright western portion is seen at lower energies. This differences can be ascribed either to an additional thermal component with electron temperature, kTe= 0.56keV from the center or, alternatively, to an increase in column density of Delta NH ~ 0.3 x 10^22 cm^-2 in the western region. In the context of the recent discovery by the NANTEN telescope of a molecular cloud apparently interacting with the western part of the supernova remnant, the second possibility seems to be the more likely scenario