HFPK 334: an unusual supernova remnant in the small magellanic cloud

We present new Australia Telescope Compact Array radio-continuum and XMM-Newton/Chandra X-ray Observatory observations of the unusual supernova remnant (SNR) HFPK 334 in the Small Magellanic Cloud (SMC). The remnant follows a shell-type morphology in the radio continuum and has a size of similar to 20 pc at the SMC distance. The X-ray morphology is similar; however, we detect a prominent point source close to the center of the SNR exhibiting a spectrum with a best-fit power law with a photon index of Gamma = 2.7 +/- 0.5. This central point source is most likely a background object and cannot be directly associated with the remnant. The high temperature, nonequilibrium conditions in the diffuse region suggest that this gas has been recently shocked and points toward a younger SNR with an age of less than or similar to 1800 yr. With an average radio spectral index of a = -0.59 +/- 0.09, we find that an equipartition magnetic field for the remnant is similar to 90 mu G, a value typical of younger SNRs in low-density environments. Also, we report the detection of scattered radio polarization across the remnant at 20 cm, with a peak fractional polarization level of 25% +/- 5%.