Observations of Pulsar Wind Nebulae with the VERITAS Array of Imaging Atmospheric Cherenkov Telescopes

TL;DR

This paper reports on VERITAS observations of three northern pulsar wind nebulae, finding no evidence of TeV gamma-ray emission, and discusses the implications for understanding particle acceleration in these objects.

Contribution

It provides the first detailed VHE gamma-ray observations of these PWNe using VERITAS, setting upper limits on their gamma-ray emission.

Findings

No TeV gamma-ray emission detected from the observed PWNe.

VERITAS sensitivity constrains the gamma-ray flux from these sources.

Results inform models of particle acceleration in pulsar wind nebulae.

Abstract

Many of the recently discovered galactic very high-energy (VHE) gamma-ray sources are associated with Pulsar Wind Nebulae, which is the most populous Galactic source category at TeV energies. The extended synchrotron nebulae of these objects observed in the X-ray band are a hallmark of the relativistic winds, generated by the young, energetic neutron stars, that interact with the matter ejected by the supernova explosion and the surrounding interstellar gas. Relativistic electrons, or protons, accelerated in the pulsar winds, or at their shock boundaries, interact with the magnetic field and low energy seed photons to produce the observed VHE gamma-ray emission. The VERITAS array of four imaging atmospheric Cherenkov telescopes was designed to study astrophysical sources of gamma rays in the energy domain from about 100 GeV up to several tens of TeV. The sensitivity of the VERITAS array allows detailed studies of the morphology and spectral features of gamma-ray emission from PWNe. Three northern sky PWNe, G75.2+0.1, G106.6+2.9, and 3C58, were observed with VERITAS during 2006. No evidence for TeV gamma-ray emission at the position of the pu lsar associated with these PWNe is demonstrated.