Suzaku Observations of the old pulsar wind nebula candidate HESS J1356-645

TL;DR

This paper reports Suzaku X-ray observations revealing an extended pulsar wind nebula around PSR J1357-6429, providing insights into the evolution of middle-aged PWNe and their association with TeV gamma-ray sources.

Contribution

First detection of a largely extended PWN around a middle-aged pulsar using Suzaku, supporting the relic PWN scenario and expanding understanding of PWN evolution.

Findings

Extended X-ray emission with a size of ~4 arcmin (~3 pc) was discovered.

The X-ray spectrum is well fitted by a power-law with photon index ~1.70.

No significant spectral variation with distance from the pulsar.

Abstract

A largely extended X-ray emission was discovered around the pulsar PSR J1357-6429 with the Suzaku deep observations. The pulsar, whose characteristic age is 7.3 kyr, is located within the TeV gamma-ray source HESS J1356-645. The extended emission is found to have a 1sigma X-ray size of ~4 arcmin, or ~3 pc at 2.4 kpc, with a small offset from the pulsar. Its X-ray spectrum is well reproduced by a simple power-law model with a photon index of 1.70+0.07-0.06. No significant spatial variation was found for the X-ray photon index as a function of distance from the pulsar. We conclude that the extended emission is associated to the pulsar wind nebula of PSR J1357-6429. This is a new sample of largely extended nebulae around middle-aged pulsars. We discuss the evolution of this PWN according to the relic PWN scenario.