Pulsar Wind Nebula candidates recently discovered by H.E.S.S

TL;DR

This paper discusses recent discoveries of pulsar wind nebula candidates by H.E.S.S., highlighting their properties, associations with pulsars, and spectral features across multiple wavelengths, advancing understanding of VHE gamma-ray sources in the Galaxy.

Contribution

It provides updated results on known sources and introduces a new candidate, offering insights into their multi-wavelength characteristics and evolution in the interstellar medium.

Findings

Detection of extended VHE gamma-ray sources associated with pulsars

Spectral steepening observed in HESS J1825-137 with distance from the pulsar

Properties of nebulae discussed across VHE, radio, and X-ray domains

Abstract

H.E.S.S. is currently the most sensitive instrument in the very-high-energy gamma-ray domain and has revealed many new sources along the Galactic Plane, a significant fraction of which seems to be associated with energetic pulsars. HESS J1825-137 and Vela X are considered to be the prototypes of such sources in which the large VHE nebula results from the whole history of the pulsar wind and the supernova remnant host, both evolving in a complex interstellar medium. These nebulae are seen to be offset from the pulsar position and, for HESS J1825-137, a spectral steepening at increasing distance from the pulsar has been measured. In this context, updated H.E.S.S. results on two previously published sources, namely HESS J1809-193 and HESS J1912+101, and preliminary results on the newly discovered HESS J1356-645, are presented. These extended VHE sources are thought to be associated with the energetic pulsars PSR J1809-1917, PSR J1913+1011 and PSR J1357-6429, respectively. Properties of each source in the VHE regime, together with those measured in the radio and X-ray domains, are discussed.