GeV gamma-ray emission from pulsar wind nebula HESS J1356-645 with Fermi-LAT

TL;DR

This study reanalyzed over 13 years of Fermi-LAT data to characterize the GeV gamma-ray emission from the pulsar wind nebula HESS J1356-645, revealing spatial, spectral, and morphological features consistent with leptonic models.

Contribution

The paper provides the first detailed GeV gamma-ray analysis of HESS J1356-645 with evidence of energy-dependent morphology and spectral modeling using leptonic scenarios.

Findings

Extended gamma-ray emission coincides with HESS J1356-645 above 5 GeV.

The spectrum follows a power law with index 1.51±0.10 from 1 GeV to 1 TeV.

Morphology of GeV emission varies with energy, similar to Vela-X.

Abstract

HESS J1356-645 is considered to be a pulsar wind nebula (PWN) associated with the pulsar PSR J1357-6429. We reanalyze the GeV gamma-ray emission in the direction of HESS J1356-645 with more than 13 years of Fermi Large Area Telescope (LAT) data. The extended gamma-ray emission above 5 GeV is found to be spatially coincident with HESS J1356-645. The spectrum in the energy range of 1 GeV-1 TeV can be described by a power law with an index of $\Gamma=1.51\pm0.10$. The broadband spectrum of HESS J1356-645 can be reproduced by a leptonic model with a broken power-law electronic spectrum. In addition, we found evidence that the morphology of the GeV emission from HESS J1356-645 varies with energy, a behavior which is similar to that of the PWN Vela-X. More broadband observations will be helpful to study the energy-dependent characteristics of HESS J1356-645.