XMM-Newton observations of the supernova remnant IC 443: II. evidence of stellar ejecta in the inner regions

TL;DR

This study uses XMM-Newton data to analyze the supernova remnant IC 443, revealing evidence of stellar ejecta, its ionization state, and providing insights into its age and physical properties.

Contribution

It offers new spatially-resolved X-ray spectral analysis of IC 443, identifying stellar ejecta and constraining the remnant's age and ionization conditions.

Findings

Detection of stellar ejecta with overabundant metals.

Estimated remnant age of approximately 4,000 years.

Less evidence for overionized plasma than previously suggested.

Abstract

We investigate the spatial distribution of the physical and chemical properties of the hot X-ray emitting plasma of the supernova remnant IC 443, in order to get 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. 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 ~4,000 yr. The presence of overionized plasma in the inner regions of IC 443, addressed in previous works, is much less evident in our observations.