XMM-Newton observation of SNR J0533–7202 in the Large Magellanic Cloud^⋆

¹ Institut für Astronomie und Astrophysik, Kepler Center for Astro and Particle Physics, Eberhard Karls Universität Tübingen, Sand 1, 72076 Tübingen, Germany
e-mail: kavanagh@astro.uni-tuebingen.de
² Max-Planck-Institut für extraterrestrische Physik, Giessenbachstraße, 85748 Garching, Germany
³ University of Western Sydney, Locked Bag 1791, Penrith, NSW 2751, Australia

Received: 20 March 2015
Accepted: 24 May 2015

Abstract

Aims. We present an X-ray study of the supernova remnant SNR J0533−7202 in the Large Magellanic Cloud (LMC) and determine its physical characteristics based on its X-ray emission.

Methods. We observed SNR J0533−7202 with XMM-Newton (background flare-filtered exposure times of 18 ks EPIC-pn and 31 ks EPIC-MOS1, EPIC-MOS2). We produced X-ray images of the supernova remnant, performed an X-ray spectral analysis, and compared the results to multi-wavelength studies.

Results. The distribution of X-ray emission is highly non-uniform, with the south-west region much brighter than the north-east. The detected X-ray emission is correlated with the radio emission from the remnant. We determine that this morphology is most likely due to the supernova remnant expanding into a non-uniform ambient medium and not an absorption effect. We estimate the remnant size to be 53.9 (±3.4) × 43.6 (±3.4) pc, with the major axis rotated ~64° east of north. We find no spectral signatures of ejecta emission and infer that the X-ray plasma is dominated by swept up interstellar medium. Using the spectral fit results and the Sedov self-similar solution, we estimate the age of SNR J0533−7202 to be ~17−27 kyr, with an initial explosion energy of (0.09−0.83) × 10⁵¹ erg. We detected an X-ray source located near the centre of the remnant, namely XMMU J053348.2−720233. The source type could not be conclusively determined due to the lack of a multi-wavelength counterpart and low X-ray counts. We found that it is likely either a background active galactic nucleus or a low-mass X-ray binary in the LMC.

Conclusions. We detected bright thermal X-ray emission from SNR J0533−7202 and determined that the remnant is in the Sedov phase of its evolution. The lack of ejecta emission prohibits us from typing the remnant with the X-ray data. Therefore, the likely Type Ia classification based on the local stellar population and star formation history reported in the literature cannot be improved upon.