2006A&A...450..585B

We report on an XMM-Newton observation of the supernova remnant (SNR) DEM L241 in the Large Magellanic Cloud. In the soft band image, the emission shows an elongated structure, like a killifish, with a central compact source. The compact source is point-like, and named XMMU J053559.3-673509. The source spectrum is reproduced well by a power-law model with a photon index of Γ=1.57 (1.51-1.62); and the intrinsic luminosity is 2.2x10³⁵erg/s in the 0.5-10.0 keV band, with an assumed distance of 50kpc. The source has neither significant coherent pulsations in 2.0x10^–3-8.0Hz nor time variabilities. Its luminosity and spectrum suggest that the source might be a pulsar wind nebula (PWN) in DEM L241. The spectral feature classifies this source as rather bright and hard PWN, which is similar to those in Kes 75 and B0540-693. The elongated diffuse structure can be divided into a ``Head'' and ``Tail'', and both have soft and line-rich spectra. Their spectra are reproduced well by a plane-parallel shock plasma (vpshock) model with a temperature of 0.3-0.4 keV, over-abundance in O and Ne, and a relative under-abundance in Fe. Such an abundance pattern and the morphology imply both that the emission is from the ejecta of the SNR and that the progenitor of DEM L241 is a very massive star, more than 20M_☉. This result is also supported by the existence of the central point source and an OB star association, LH 88. The total thermal energy and plasma mass are ∼4x10⁵⁰erg and ∼200M_☉, respectively.