Detection of the Neutral Iron Line from the Supernova Remnant W49B with Suzaku

Recent studies of supernova remnants (SNRs) have revealed that some SNRsexhibit a neutral iron line emission at 6.4 keV. This line has been proposed tooriginate from the interaction of high-energy particles formed in the SNR shellwith the surrounding cold matter. We searched for the neutral iron lineemission in the SNR W49B. Significant detection of the 6.4 keV line is found inthe northwest region, close to the molecular cloud interacting with the SNRshell. In addition, an excess emission at 8-9 keV, in which K_gamma, K_delta,and K_epsilon lines of He-like iron exist, is also significantly found in theregion where the radio shell is not bright. We discuss the origin of the 6.4keV line and the excess emission at 8-9 keV.