Discovery of the VHE gamma-ray source HESS J1641-463

TL;DR

This paper reports the discovery of a new very high energy gamma-ray source, HESS J1641-463, detected in the Galactic plane with significant flux and a hard spectrum, potentially linked to a supernova remnant.

Contribution

The paper presents the first detection and characterization of HESS J1641-463, a new VHE gamma-ray source, including its spectral properties and possible origin.

Findings

Detected HESS J1641-463 at 8.6 sigma significance

Source has a flux of 1.7% of Crab at >1 TeV

Hard photon index of approximately 2

Abstract

A new TeV source, HESS J1641-463, has been serendipitously discovered in the Galactic plane by the High Energy Stereoscopic System (H.E.S.S.) at a significance level of 8.6 standard deviations. The observations of HESS J1641-463 were performed between 2004 and 2011 and the source has a moderate flux level of 1.7% of the Crab Nebula flux at E > 1 TeV. HESS J1641-463 has a rather hard photon index of 1.99 +- 0.13_stat +- 0.20_sys. HESS J1641-463 is positionally coincident with the radio supernova remnant SNR G338.5+0.1, but no clear X-ray counterpart has been found in archival Chandra observations of the region. Different possible VHE production scenarios will be discussed in this contribution.