A Search for Short-term Variability in the Very High Energy Gamma-ray Emission from the Crab Nebula

TL;DR

This study investigates short-term variability in the Crab Nebula's very high energy gamma-ray emission over a decade, finding no significant flaring activity but setting the stage for future sensitivity assessments.

Contribution

It provides the first systematic search for short-term VHE gamma-ray variability in the Crab Nebula using 10 years of archival data.

Findings

No significant flaring activity detected.

Data set covers 2001-2011 from Whipple telescope.

Simulations ongoing to determine detection sensitivity.

Abstract

The Crab Nebula has long been considered a standard candle in high energy astrophysics, but in recent years this assumption has been strongly contradicted in keV-GeV wavebands. In light of these developments, a search for variability is being performed on the nebula at Very High Energies (VHE; E>300 GeV), the preliminary results of which are presented here. This initial study is based on 10 years (2001-2011) of archival data from the Whipple 10 m telescope. The data set was searched for evidence of variability on the timescales of 1, 7, and 14 days. To date, no significant flaring activity has been found, but simulations are in progress to determine the level of variability that would be detected.