Revealing New Physical Structures in the Supernova Remnant N63A through Chandra Imaging Spectroscopy

Abstract

We present Chandra X-ray observationsof the supernova remnant (SNR) N63A in the Large Magellanic Cloud(LMC). N63A, one of the brightest LMC remnants, is embedded in an H IIregion and is probably associated with an OB association. The opticalremnant consists of three lobes of emission contained within theapproximately 3 times larger X-ray remnant. Our Chandra data reveal anumber of new physical structures in N63A. The most striking of theseare the several ``crescent''-shaped structures located beyond themain shell that resemble similar features seen in the Vela SNR. InVela, these have been interpreted as arising from high-speed clumpsof supernova ejecta interacting with the ambient medium. Anotherdistinct feature of the remnant is a roughly triangular ``hole'' inthe X-ray emission near the location of the optical lobes and thebrightest radio emission. X-ray spectral analysis shows that thisdeficit of emission is the result of absorption by an interveningdense cloud with a mass of ~450 M solar that is currentlybeing engulfed by the remnant's blast wave. We also find that therim of the remnant, as well as the crescent-shaped features, hasconsiderably softer X-ray spectra than the interior. Limits on hardX-ray emission rule out a young, energetic pulsar in N63A, but thepresence of an older or less active one, powering a wind nebula with aluminosity less than ~4�10 34 ergs s -1, is allowed.