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Abstract The centroid energy of the Fe K α line has been used to identify the progenitors of supernova remnants (SNRs). These investigations generally considered the energy of the centroid derived from the spectrum of the entire remnant. Here we use XMM-Newton data to investigate the Fe K α centroid in 6 SNRs: 3C 397, N132D, W49B, DEM L71, 1E 0102.2-7219, and Kes 73. In Kes 73 and 1E 0102.2-7219, we fail to detect any Fe K α emission. We report a tentative first detection of Fe K α emission in SNR DEM L71 with a centroid energy consistent with its Type Ia designation. In the remaining remnants, the spatial and spectral sensitivity is sufficient to investigate spatial variations of the Fe K α centroid. We find in N132D and W49B that the centroids in different regions are consistent with those derived from the overall spectrum, although not necessarily with the remnant type identified via other means. However, in SNR 3C 397, we find statistically significant variation in the centroid of up to 100 eV, aligning with the variation in the density structure around the remnant. These variations span the intermediate space between centroid energies signifying core-collapse (CC) and Type Ia remnants. Shifting the dividing line downwards by 50 eV can place all the centroids in the CC region, but contradicts the remnant type obtained via other means. Our results show that caution must be used when employing the Fe K α centroid of the entire remnant as the sole diagnostic for typing a remnant.
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An exploration of X-ray Supernova remnants in the Milky Way and nearby galaxies
ABSTRACT We probe the environmental properties of X-ray supernova remnants (SNRs) at various points along their evolutionary journey, especially the S-T phase, and their conformance with theoretically derived models of SNR evolution. The remnant size is used as a proxy for the age of the remnant. Our data set includes 34 Milky Way, 59 Large Magellanic Cloud (LMC), and 5 Small Magellanic Cloud (SMC) SNRs. We select remnants that have been definitively typed as either core-collapse (CC) or Type Ia supernovae, with well-defined size estimates, and a thermal X-ray flux measured over the entire remnant. A catalog of SNR size and X-ray luminosity is presented and plotted, with ambient density and age estimates from the literature. Model remnants with a given density, in the Sedov-Taylor (S-T) phase, are overplotted on the diameter-versus-luminosity plot, allowing the evolutionary state and physical properties of SNRs to be compared to each other, and to theoretical models. We find that small, young remnants are predominantly Type Ia remnants or high luminosity CCs, suggesting that many CC SNRs are not detected until after they have emerged from the progenitor’s wind-blown bubble. An examination of the distribution of SNR diameters in the Milky Way and LMC reveals that LMC SNRs must be evolving in an ambient medium which is 30 per cent as dense as that in the Milky Way. This is consistent with ambient density estimates for the Galaxy and LMC.
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- Award ID(s):
- 1911061
- PAR ID:
- 10412876
- Publisher / Repository:
- Oxford University Press
- Date Published:
- Journal Name:
- Monthly Notices of the Royal Astronomical Society
- Volume:
- 514
- Issue:
- 1
- ISSN:
- 0035-8711
- Page Range / eLocation ID:
- p. 728-743
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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