Discovery of an X-ray nebula around PSR J1718-3825 and implications for the nature of the gamma-ray source HESS J1718-385

TL;DR

This study reports the discovery of an X-ray nebula around pulsar PSR J1718-3825, providing insights into the particle acceleration and magnetic fields in the associated gamma-ray source HESS J1718-385, through combined X-ray and gamma-ray observations.

Contribution

It presents the first X-ray detection of the nebula around PSR J1718-3825 and discusses its implications for understanding the nature of the gamma-ray source HESS J1718-385.

Findings

Detected a hard X-ray source at PSR J1718-3825's position

Found diffuse X-ray emission near the pulsar

Set limits on X-ray emission from HESS J1718-385

Abstract

Combined X-ray synchrotron and inverse-Compton gamma-ray observations of pulsar wind nebulae (PWN) may help to elucidate the processes of acceleration and energy loss in these systems. In particular, such observations provide constraints on the particle injection history and the magnetic field strength in these objects. The newly discovered TeV gamma-ray source HESS J1718-385 has been proposed as the likely PWN of the high spin-down luminosity pulsar PSR J1718-3825. The absence of previous sensitive X-ray measurements of this pulsar, and the unusual energy spectrum of the TeV source, motivated observations of this region with XMM-Newton. The data obtained reveal a hard spectrum X-ray source at the position of PSR 1718-3825 and evidence for diffuse emission in the vicinity of the pulsar. We derive limits on the keV emission from the centroid of HESS J1718-385 and discuss the implications of these findings for the PWN nature of this object.