Chandra and NuSTAR Observations of Supernova Remnant RX J1713.7-3946

Galactic cosmic rays are widely thought to be accelerated at supernova remnants (SNRs). SNR RX J1713.7-3946 is the strong sources of nonthermal radiation, making it one of the most well studied particle accelerators in our Galaxy. From the Chandra measurement of the proper motions in the northwest region of RX J1713.7-3946, the blast-wave shock speed is estimated as 3900 km/s. This relatively fast shock velocity, combined with the standard analytic solutions that describe the hydrodynamical properties of SNR evolution, supports the connection with SN393, and suggests that RX J1713.7-3946 would not have exited the ejecta-dominated phase, implying that the energy of accelerated particles has not reached the maximum yet. We have recently performed hard X-ray observations of RX J1713.7-3946 with NuSTAR (3 79 keV), providing fisrt imaging observations of RX J1713.7-3946 at the hard X-ray band above 10 keV. In preliminary fashion, we present spatially-resolved spectral analysis of the northwest part of this remnant and report the detection of an extremely hard X-ray component with NuSTAR.