Discovery of Fast-Moving X-Ray--Emitting Ejecta Knots in the Oxygen-Rich Supernova Remnant Puppis A

TL;DR

This paper reports the discovery of fast-moving, metal-rich X-ray emitting ejecta knots in the supernova remnant Puppis A, revealing complex ejecta dynamics and supporting models of recoiled supernova ejecta.

Contribution

It presents the first detection of X-ray ejecta knots in Puppis A with detailed spectral analysis, linking optical and X-ray observations to ejecta recoil mechanisms.

Findings

Identification of metal-rich ejecta knots with high velocities.

Spectral evidence of blue-shifted line emission indicating rapid motion.

Different Doppler velocities suggest multiple knots along the line of sight.

Abstract

We report on the discovery of fast-moving X-ray--emitting ejecta knots in the Galactic Oxygen-rich supernova remnant Puppis A from XMM-Newton observations. We find an X-ray knotty feature positionally coincident with an O-rich fast-moving optical filament with blue-shifted line emission located in the northeast of Puppis A. We extract spectra from northern and southern regions of the feature. Applying a one-component non-equilibrium ionization model for the two spectra, we find high metal abundances relative to the solar values in both spectra. This fact clearly shows that the feature originates from metal-rich ejecta. In addition, we find that line emission in the two regions is blue-shifted. The Doppler velocities derived in the two regions are different with each other, suggesting that the knotty feature consists of two knots that are close to each other along the line of sight. Since fast-moving O-rich optical knots/filaments are believed to be recoiled metal-rich ejecta, expelled to the opposite direction against the high-velocity central compact object, we propose that the ejecta knots disclosed here are also part of the recoiled material.