The Galactic Supernova Remnant W49B Likely Originates from a Jet-Driven, Core-Collapse Explosion

TL;DR

This study uses deep X-ray observations to analyze the supernova remnant W49B, revealing evidence that it originated from a jet-driven, bipolar core-collapse supernova, and notably lacks an associated neutron star.

Contribution

It provides the first evidence in the Milky Way that W49B originated from a jet-driven, bipolar core-collapse supernova, based on detailed spectral and morphological analysis.

Findings

Metal abundances match bipolar/jet-driven supernova models

No neutron star detected in W49B

W49B likely from a Type Ib/Ic supernova explosion

Abstract

We present results from a 220-ks observation of the galactic supernova remnant (SNR) W49B using the Advanced CCD Imaging Spectrometer (ACIS) on board the Chanrda X-ray Observatory. We exploit these data to perform detailed spatially-resolved spectroscopic analyses across the SNR with the aim to investigate the thermodynamic properties and explosive origin of W49B. We find substantial variation in the electron temperature and absorbing column toward W49B, and we show that the mean metal abundances are consistent with the predicted yields in models of bipolar/jet-driven core-collapse SNe. Furthermore, we set strict upper limits on the X-ray luminosity of any undetected point sources, and we exclude the presence of a neutron star associated with W49B. We conclude that the morphological, spectral, and environmental characteristics of W49B are indicative of a bipolar Type Ib/Ic SN origin, making it the first of its kind to be discovered in the Milky Way.