Suzaku observations of ejecta-dominated Galactic supernova remnant G346.6-0.2

Abstract

We present here the results of an X-ray analysis of Galactic supernova remnant G346.6-0.2 observed with Suzaku. K-shell emission lines of Mg, Si, S, Ca and Fe are detected clearly for the first time. Strong emission lines of Si and S imply that the X-ray emission nature of G346.6-0.2 is ejecta-dominated. The ejecta-dominated emission is well fitted by a combined model consisting of a thermal plasma in non-equilibrium ionization and a non-thermal component, which can be regarded as synchrotron emission with a photon index of Γ∼ 0.6. An absorbing column density of N_H∼ 2.1 × 10²² cm^-2 is obtained from the best fit, implying a high-density medium, high electron temperature of kT_e∼ 1.2 keV and ionization time-scale of n_et∼ 2.9 × 10¹¹ cm^-3 s, indicating that this remnant may be far from full ionization equilibrium. The relative abundances from the ejecta show that the remnant originates from a Type Ia supernova explosion.