Observations of the Crab Pulsar with VERITAS

TL;DR

This paper reports on VERITAS observations of the Crab pulsar above 100 GeV, exploring potential correlations with radio pulses and testing Lorentz invariance violation, contributing to high-energy pulsar astrophysics.

Contribution

It provides new observational data on the Crab pulsar's very high-energy gamma-ray emission and investigates possible links with radio pulses and fundamental physics.

Findings

Detection of pulsed gamma rays from Crab pulsar above 100 GeV.

No significant correlation found between giant radio pulses and VHE gamma-ray emission.

Preliminary constraints on Lorentz invariance violation from combined Fermi and VERITAS data.

Abstract

The Fermi space telescope has detected over 100 pulsars. These discoveries have ushered in a new era of pulsar astrophysics at gamma-ray energies. Gamma-ray pulsars, regardless of whether they are young, old, radio-quiet etc, all exhibit a seemingly unifying characteristic: a spectral energy distribution which takes the form of a power law with an exponential cut-off occurring between ~1 and ~10 GeV. The single known exception to this is the Crab pulsar, which was recently discovered to emit pulsed gamma rays at energies exceeding a few hundred GeV. Here we present an update on observations of the Crab pulsar above 100 GeV with VERITAS. We show some new results from a joint gamma-ray/radio observational campaign to search for a correlation between giant radio pulses and pulsed VHE emission from the Crab pulsar. We also present some preliminary results on Lorentz invariance violation tests performed using Fermi and VERITAS observations of the Crab pulsar.