G4.8+6.2, a possible kilonova remnant?

TL;DR

This paper explores the possibility that the G4.8+6.2 remnant is a kilonova remnant linked to the AD 1163 guest star, suggesting young KNRs may have distinct observational features, but definitive proof requires further data.

Contribution

It proposes a potential historical association between G4.8+6.2 and a kilonova event from AD 1163, offering a new perspective on identifying young kilonova remnants.

Findings

G4.8+6.2 may be a kilonova remnant associated with AD 1163

Young KNRs could have large diameters and low surface brightness

Further observations are necessary to confirm the hypothesis

Abstract

Kilonova explosions typically release $\sim 10^{50-51}$ erg in kinetic energy, which is sufficient to constitute a kilonova remnant (KNR); however, it has not yet been confirmed. In this work, we investigate the probable association between G4.8+6.2 and the guest star of AD 1163, which is recorded by the Korea ancient astronomers. Although the evidence available is insufficient to draw a definite conclusion, it is at least theoretically self-consistent that the guest star of AD 1163 was a historical kilonova associated with G4.8+6.2, considering the possible short visible timescale of AD 1163, the relatively high Galactic latitude of G4.8+6.2, and that G4.8+6.2 is spatially coincident with the guest star of AD 1163. Further observation of G4.8+6.2 is needed to test our hypothesis. If our interpretation is correct, our results indicate that young KNRs should have a large diameter and low surface brightness, unlike other young supernova remnants.