Ejecta detection in the middle-aged Galactic supernova remnant G296.1-0.5 observed with Suzaku

Abstract

In this paper, we report the detection of ejecta in the middle-aged Galactic supernova remnant G296.1-0.5 with the X-ray Imaging Spectrometer onboard the Suzaku satellite. The spectra of three lobes, north, south-east and south-west and interlobe regions, consist of soft (0.3-2.0 keV) emission originated from non-equilibrium ionization plasma. In north, south-east and interlobe regions, the thermal emission can be represented by a one-component non-equilibrium ionization (VNEI) model, in south-west region it can be represented by two-component VNEI model. The spectra of studied regions have lines of N, O, Ne, Mg and Si elements. Si emission from this remnant is shown for the first time in this work. Enhanced abundances of Ne, Mg and Si elements obtained show the ejecta contribution in all regions. Assuming that the remnant is in Sedov phase, we obtained ambient density n₀∼ 0.45 cm^-3, age t ∼ 2.8 × 10⁴ yr, shock velocity V_s∼ 320 km s^-1, shock temperature T_s∼ 1.2 × 10⁶ K and swept-up mass M_sw∼ 340 M_⊙ at an adopted distance of d= 3 kpc.