CHANDRAANDXMM-NEWTONSTUDIES OF THE SUPERNOVA REMNANT G292.2-0.5 ASSOCIATED WITH THE PULSAR J1119-6127

Abstract

We present the first detailed imaging and spatially resolved spectroscopic study of the Galactic supernova remnant G292.2-0.5, associated with the high-magnetic field radio pulsar J1119-6127, using Chandra and XMM-Newton. The high-resolution X-ray images reveal a partially limb-brightened morphology in the west, with diffuse emission concentrated towards the interior of the remnant unlike the complete shell-like morphology observed at radio wavelengths. The spectra of most of the diffuse emission regions within the remnant are best described by a thermal+non-thermal model. The thermal component is described by a plane-parallel, non-equilibrium ionization plasma model with a temperature ranging from 1.3 keV in the western side of the remnant to 2.3 keV in the east, a column density increasing from 1.0e22 cm^-2 in the west to 1.8e22 cm^-2 in the east, and a low ionization timescale ranging from 5.7e9 cm^-3 s in the SNR interior to 3.6e10 cm^-3 s in the western side - suggestive of expansion of a young remnant in a low-density medium. The spatial and spectral differences across the SNR are consistent with the presence of a dark cloud in the eastern part of the SNR, absorbing the soft X-ray emission. The spectra from some of the regions also show slightly enhanced metal abundances from Ne, Mg and Si, hinting at the first evidence for ejecta heated by the reverse shock. Comparing our inferred metal abundances to core-collapse nucleosynthesis models yields, we estimate a high progenitor mass of ~30 solar mass suggesting a type Ib/c supernova. We confirm the presence of non-thermal hard X-ray emission from regions close to the pulsar. We estimate an SNR age range between 4.2 kyr (free expansion phase) and 7.1 kyr (Sedov phase), a factor of a few higher than the measured pulsar's age upper limit of 1.9 kyr.