XMM-Newton observations of the supernova remnant IC 443
II. Evidence of stellar ejecta in the inner regions
INAF - Istituto di Astrofisica Spaziale e Fisica Cosmica, Sezione di Palermo, via Ugo la Malfa 153, 90146 Palermo, Italy e-mail: firstname.lastname@example.org
2 Dipartimento di Scienze Fisiche ed Astronomiche, Sezione di Astronomia, Università di Palermo, Piazza del Parlamento 1, 90134 Palermo, Italy
3 INAF - Osservatorio Astronomico di Palermo, Piazza del Parlamento 1, 90134 Palermo, Italy
Accepted: 29 March 2008
Aims. We investigate the spatial distribution of the physical and chemical properties of the hot X-ray emitting plasma of the supernova remnant IC 443, to derive important constraints on its ionization stage, on the progenitor supernova explosion, on the age of the remnant, and its physical association with a close pulsar wind nebula.
Methods. We present XMM-Newton images of IC 443, a median photon energy map, silicon and sulfur equivalent width maps, and a spatially resolved spectral analysis of a set of homogeneous regions.
Results. The hard X-ray thermal emission (1.4–5.0 keV) of IC 443 displays a centrally-peaked morphology, its brightness peaks being associated with hot (kT > 1 keV) X-ray emitting plasma. A ring-shaped structure, characterized by high values of equivalent widths and median photon energy, encloses the PWN. Its hard X-ray emission is spectrally characterized by a collisional ionization equilibrium model, and strong emission lines of Mg, Si, and S, requiring oversolar metal abundances. Dynamically, the location of the ejecta ring suggests an SNR age of ~4000 yr. The presence of overionized plasma in the inner regions of IC 443, addressed in previous works, is much less evident in our observations.
Key words: ISM: supernova remnants / ISM: individual objects: IC 443 / pulsars: individual: CXOU J061705.3+222127 / X-rays: ISM
© ESO, 2008