The Properties of the Progenitor Supernova, Pulsar Wind, and Neutron Star inside PWN G54.1+0.3

TL;DR

This study models the evolution of PWN G54.1+0.3 to determine properties of its progenitor supernova, neutron star, and pulsar wind, providing insights into their characteristics and interactions within the supernova remnant.

Contribution

It introduces a detailed dynamical and radiative model to infer properties of the progenitor star, neutron star, and pulsar wind in PWN G54.1+0.3, which were previously difficult to measure directly.

Findings

Progenitor was a 15-20 Solar Mass star in a star cluster.

Neutron star initially spun with a period of 30-80 ms.

Over 99.9% of pulsar energy injected as relativistic particles.

Abstract

The evolution of a pulsar wind nebula (PWN) inside a supernova remnant (SNR) is sensitive to properties of the central neutron star, pulsar wind, progenitor supernova, and interstellar medium. These properties are both difficult to measure directly and critical for understanding the formation of neutron stars and their interaction with the surrounding medium. In this paper, we determine these properties for PWN G54.1+0.3 by fitting its observed properties with a model for the dynamical and radiative evolution of a PWN inside an SNR. Our modeling suggests that the progenitor of G54.1+0.3 was an isolated ~15-20 Solar Mass star which exploded inside a massive star cluster, creating a neutron star initially spinning with period ~30-80ms. We also find that >99.9% of the pulsar's rotational energy is injected into the PWN as relativistic electrons and positrons whose energy spectrum is well characterized by a broken power-law. Lastly, we propose future observations which can both test the validity of this model and better determine the properties of this source -- in particular, its distance and the initial spin period of the central pulsar.