Discovery of two candidate pulsar wind nebulae in very-high-energy gamma rays

Abstract

Context: We present the discovery of two very-high-energy γ-ray sources in an ongoing systematic search for emission above 100 GeV from pulsar wind nebulae in survey data from the HESS telescope array.

Aims: Imaging Atmospheric Cherenkov Telescopes are ideal tools for searching for extended emission from pulsar wind nebulae in the very-high-energy regime. HESS, with its large field of view of 5° and high sensitivity, gives new prospects for the search for these objects.

Methods: An ongoing systematic search for very-high-energy emission from energetic pulsars over the region of the Galactic plane between -60° < l < 30°, -2° < b < 2° is performed. For the resulting candidates, the standard HESS analysis was applied and a search for multi-wavelength counterparts was performed.

Results: We present the discovery of two new candidate γ-ray pulsar wind nebulae, HESS J1718-385 and HESS J1809-193.

Conclusions: HESS has proven to be a suitable instrument for pulsar wind nebula searches.