Parkes radio and NuSTAR X-ray observations of the composite supernova remnant B0453-685 in the large magellanic cloud

Gamma-ray emission is observed coincident in position to the evolved, composite supernova remnant (SNR) B0453-685. Prior multiwavelength investigations of the region indicate that the pulsar wind nebula (PWN) within the SNR is the most likely origin for the observed gamma rays, with a possible pulsar contribution that becomes significant at energies below E ∼ 5 GeV. Constraints on the PWN hard X-ray spectrum are important for the most accurate broadband representation of PWN emission and determining the presence of a gamma-ray pulsar component. The results of Parkes radio and Nuclear Spectroscopic Telescope Array (NuSTAR) X-ray observations are presented on PWN B0453-685. We perform a search for the central pulsar in the new Parkes radio data, finding an upper limit of 12 μJy. A pulsation search in the new NuSTAR observations additionally provides a 3σ upper limit on the hard X-ray pulsed fraction of 56%. The PWN is best characterized with a photon index ΓX = 1.91 ± 0.20 in the 3-78 keV NuSTAR data, and the results are incorporated into existing broadband models. Last, we characterize a serendipitous source detected by Chandra and NuSTAR that is considered a new high-mass X-ray binary candidate.