G189.6+03.3: The first complete X-ray view provided by SRG/eROSITA

¹ Max-Planck-Institut für extraterrestrische Physik, Giessenbachstraße, 85748 Garching, Germany
e-mail: fcam@mpe.mpg.de
² Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany

Received: 27 June 2023
Accepted: 28 September 2023

Abstract

Context. G189.6+03.3 and IC443 are two examples of supernova remnants (SNRs) located in a region rich in gas and dust, and spatially close to the HII region S249. So far, the actual shape of IC443 is believed to be given by the past action of multiple supernova (SN) explosions, while a third unrelated SN might have originated G189.6+03.3.

Aims. Although the IC443 nebula has been extensively observed in several bands, on the contrary, the nearby and much weaker SNR G189.6+03.3, discovered in 1994 with ROSAT, has received very little attention. Given the relatively large extent of this second remnant, the new dataset provided by the X-ray telescope eROSITA on board the Spectrum Roentgen Gamma mission provides a unique opportunity to characterize it more in detail.

Methods. We provide a full spectral characterization of G189.6+03.3 emission for the first time, together with new images covering the whole remnant. As one of the leading hypotheses is that its emission partially overlaps with the emission from IC443, we test this scenario by dividing the remnant into several regions from which we extracted the spectra.

Results. The new X-ray images provided by eROSITA show an elongated structure. Together with the detection of supersolar abundances of O, Mg, Ne, and Si and a subsolar abundance of Fe, these features could be an indication of a faint SN explosion. The X-ray spectra also highlight the presence of a 0.7 keV plasma component across all of the regions, together with an almost uniform column density.

Conclusions. The ubiquitous presence of the 0.7 keV plasma component is a strong indication that G189.6+03.3 completely overlaps with IC443. We propose that the progenitors of G189.6+03.3 and IC443 could have been expelled from the same binary or multiple system, and this originated two explosions at different times and in different positions.