New Constraints on the Energetics, Progenitor Mass, and Age of the Supernova Remnant G292.0+1.8 Containing Psr J1124-5916

We present spatially resolved spectroscopy of the supernova remnant (SNR) G292.0+1.8 with the Chandra X-ray observatory. This composite-type SNR contains the 135 ms pulsar, J1124-5916, recently discovered by Camilo and coworkers. We apply non-equilibrium ionization (NEI) models to fit the ejecta-dominated regions and to identify the blast wave of the supernova explosion. By comparing the derived abundances with those predicted from nucleosynthesis models, we estimate a progenitor mass of 30–40 M⊙. We derive the intrinsic parameters of the supernova explosion such as its energy, the age of the SNR, the blast wave velocity, and the swept-up mass. In the Sedov interpretation, our estimated SNR age of 2,600+250 −200 years is close to the pulsar’s characteristic age of 2,900 years. This confirms the pulsar/SNR association and relaxes the need for the pulsar to have a non-canonical value for the braking index, a large period at birth or a large transverse velocity. We discuss the properties of the pulsar wind nebula (PWN) in the light of the Kennel and Coroniti model and estimate the pulsar wind magnetization parameter. We also report the first evidence for steepening of the power law spectral index with increasing radius from the pulsar, a result that is expected from synchrotron losses and is reminiscent of Crab-like PWNe. Subject headings: ISM: individual (G292.0+1.8, MSH 11-54, PSR J1124-5916) — ISM: abundances — supernova remnants — X-rays: ISM