Comparing supernova remnants around strongly magnetized and canonical pulsars

TL;DR

This study compares supernova remnants around magnetars and normal pulsars, finding no significant differences in X-ray emission lines or luminosities, which suggests similar supernova environments regardless of neutron star magnetic strength.

Contribution

It provides a comprehensive re-analysis of SNRs around magnetars and compares them with other neutron star types, revealing no significant differences in X-ray properties.

Findings

No significant difference in emission lines between SNRs of magnetars and other neutron stars.

X-ray luminosities of SNRs around magnetars are comparable to those around normal pulsars.

Similar percentage of magnetars and normal pulsars have detectable SNRs at comparable ages.

Abstract

The origin of the strong magnetic fields measured in magnetars is one of the main uncertainties in the neutron star field. On the other hand, the recent discovery of a large number of such strongly magnetized neutron stars, is calling for more investigation on their formation. The first proposed model for the formation of such strong magnetic fields in magnetars was through alpha-dynamo effects on the rapidly rotating core of a massive star. Other scenarios involve highly magnetic massive progenitors that conserve their strong magnetic moment into the core after the explosion, or a common envelope phase of a massive binary system. In this work, we do a complete re-analysis of the archival X-ray emission of the Supernova Remnants (SNR) surrounding magnetars, and compare our results with all other bright X-ray emitting SNRs, which are associated with Compact Central Objects (CCOs; which are proposed to have magnetar-like B-fields buried in the crust by strong accretion soon after their formation), high-B pulsars and normal pulsars. We find that emission lines in SNRs hosting highly magnetic neutron stars do not differ significantly in elements or ionization state from those observed in other SNRs, neither averaging on the whole remnants, nor studying different parts of their total spatial extent. Furthermore, we find no significant evidence that the total X-ray luminosities of SNRs hosting magnetars, are on average larger than that of typical young X-ray SNRs. Although biased by a small number of objects, we found that for a similar age, there is the same percentage of magnetars showing a detectable SNR than for the normal pulsar population.