The precessing jet axis of the supernova remnant 3C 397

TL;DR

This paper presents evidence of precessing jets shaping the supernova remnant 3C 397, suggesting jet activity played a key role in its explosion, similar to other enigmatic remnants like W49B.

Contribution

It identifies an S-shaped jet feature in 3C 397 and proposes two novel jet-driven explosion scenarios, advancing understanding of supernova mechanisms.

Findings

Identification of an S-shaped jet structure in 3C 397

Similarity between 3C 397 and W49B in jet features

Support for jet-driven supernova explosion models

Abstract

We identify an S-shaped morphological feature in the enigmatic supernova remnant (SNR) 3C 397, which we attribute to the shaping by a precessing pair of jets during the explosion. We identify an S-shaped, faint region composed of two bubbles, located to the north and south of the center, between two X-ray-bright sides. We attribute the S-shape to a pair of precessing jets that were part of the explosion process. The identification of a main jet axis in SNR 3C 397 increases its similarity to the enigmatic SNR W49B. We discuss two possible scenarios for SNR 3C 397 and W49B. (1) The thermonuclear common-envelope-jet supernova scenario, which was suggested before for W49B, where a neutron star destroys a white dwarf and accretes part of the white dwarf's material via an accretion disk that undergoes a thermonuclear outburst and launches the jets. (2) The collapse-induced thermonuclear jet-driven explosion, which is a core-collapse supernova driven by jets, as in the majority of, or even all, core-collapse supernovae, and in addition, there is a thermonuclear outburst of a rare helium-oxygen mixed layer in the core, which is triggered by the core collapse. Our study emphasizes the primary role of jets even in the enigmatic SNR 3C 397.