Suzaku Discovery of Fe K-Shell Line from the O-Rich SNR G292.0+1.8
  We report the Suzaku/XIS results of the Galactic oxygen-rich supernova remnant (SNR), G292.0+1.8, a remnant of a core-collapse supernova. The X-ray spectrum of G292.0+1.8 consists of two type plasmas, one is in collisional ionization equilibrium (CIE) and the other is in non-equilibrium ionization (NEI). The CIE plasma has nearly solar abundances, and hence would be originated from the circumstellar and interstellar mediums. The NEI plasma has super-solar abundances, and the abundance pattern indicates that the plasma originates from the supernova ejecta with a main sequence of 30-35 Msolar. Iron K-shell line at energy of 6.6 keV is detected for the first time in the NEI plasma. 
Fumiyoshi Kamitsukasa, Katsuji Koyama, Hiroshi Tsunemi, Kiyoshi   Hayashida, Hiroshi Nakajima, Hiroaki Takahashi, Shutaro Ue...
astro-ph.HE