The Peculiar Ejecta Rings in the O-Rich Supernova Remnant Puppis A: Evidence of a Binary Interaction?

TL;DR

This study investigates the peculiar high-velocity, chemically diverse ejecta rings in Puppis A, revealing their turbulent, shock-excited nature and suggesting they may be shaped by binary star interactions during supernova explosion.

Contribution

First integral field spectroscopy analysis of the Puppis A ejecta rings, providing detailed composition, velocity, and turbulence data, and proposing a binary interaction origin.

Findings

Ejecta rings are nitrogen-rich, oxygen-rich, and contain sulfur, with velocities up to 1350 km/s.

The structures are turbulent, shock-excited, and contain about 0.5 solar masses of metal-rich material.

Chemical and velocity patterns suggest a binary interaction shaping the ejecta.

Abstract

Near the center of the Puppis A SNR a series of nested optically emitting rings of high velocity ejecta (known as `the Swirl') were identified several decades ago by Winkler et al. (1989). To date no follow-up observations of these rings have been published, and their physical origin has remained a mystery. We present results of integral field spectroscopy of the Swirl using the Wide Field Integral Spectrograph (\wifes) on the 2.3\,m telescope at Siding Spring Observatory in Australia. The outermost ring exhibits a nitrogen-rich spectrum blueshifted to 1350 km/s, with smaller blueshifted rings within the first exhibiting mostly oxygen-rich spectra moving at 1000 km/s and 750 km/s. The structures are connected by material of intermediate velocity and variable composition, including sulfur-rich material. The Swirl is turbulent and shock excited, and contains as much as 0.5 M$_{\odot}$ of metal-rich material. The chemical composition and exclusively blueshifted radial velocities of the Swirl are consistent with progressively deeper nucleosynthetic layers in a massive progenitor star. We suggest the possibility that the Swirl marks a `funnel' carved into the supernova ejecta by a close, massive binary companion at the moment of explosion.