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 G292.0+1.8, a remnant of a core-collapse supernova. The X-ray spectrum of G292.0+1.8 consists of two types of plasma, 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 30–35M . The iron K-shell line at an energy of 6.6 keV is detected for the first time in the NEI plasma.