2018ApJ...861..154S

The Large Magellanic Cloud supernova remnant J0453-6655 in the H II region N4 has been observed with XMM-Newton and with Chandra. Almost all of the diffuse X-ray emission is from within a 3.'5 x 2.'3 region of bright optical filaments, and X-ray results from XMM-Newton and Chandra are very similar. Spectra indicate that the plasma is close to equilibrium and that the remnant is likely the result of a Type II supernova powered by the collapse of a <12 M_☉ star. Composition, density, and mass of the X-ray-emitting plasma are derived, and the age of the remnant is estimated to be 60-80 kyr. There is an apparent blowout of energy into an adjoining cavity. Because cooling neutron stars are objects of interest, the surrounding sky is searched for possible compact remnants of the core. There are six point-like sources within the remnant, all rather faint. Two are probably background active galactic nuclei. The others have soft spectral components and no IR counterparts, but, with the present data, none can be proved to be a neutron star. They do represent upper limits to any neutron star luminosity.