High resolution spectroscopy and emission line imaging of DEM L 71 with XMM-Newton

¹ SRON National Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht, The Netherlands
² Columbia Astrophysics Laboratory, Columbia University, 550 West 1 20th Street, New York, NY 10027, USA
³  fellow

Corresponding author: K. J. van der Heyden, K.J.van.der.Heyden@sron.nl

Received: 5 February 2003
Accepted: 15 April 2003

Abstract

The X-ray emission from the supernova remnant DEM L 71 is measured and analysed using the high-resolution cameras and spectrometers on board XMM-Newton. The spectrum from the outer shell is reproduced very well by two plasma components of kT_e = 0.3 and 0.8 keV. The abundance value from this shell is consistent with the average LMC values. More extreme temperature variations are possibly indicated by spatial variations in the forbidden/resonance line ratio, which could imply that in some regions the plasma is cooling dramatically and recombining. However, an alternative and equally interesting possibility is that the variation in forbidden/resonance ratios is due to resonant scattering, which would reduce resonance line emission along lines of sight with a high column density. The inner region is hotter ( keV) and shows enhanced Fe and Si abundances. We estimate the Fe and Si ejecta mass to be 0.7–1.1 and 0.1–0.15, respectively. The morphology, mass estimates and abundances strongly suggest that DEM L 71 is the result of a type Ia explosion, as indicated by previous measurements.