On the time variability of gamma-ray sources: A numerical analysis of variability indices

Abstract

We present a Monte Carlo analysis of the recently introduced variability indices $\tau$ (Tompkins 1999) and $I$ (Zhang et al. 2000 & Torres et al. 2001) for $\gamma$-ray sources. We explore different variability criteria and prove that these two indices, despite the very different approaches used to compute them, are statistically correlated (5 to 7$\sigma$). This conclusion is maintained also for the subset of AGNs and high latitude ($|b|>10$ deg) sources, whereas the correlation is lowered for the low latitude ones, where the influence of the diffuse galactic emission background is strong.

Small changes to match published version in Astronomische Nachrichten (2001). Paper accepted in July 2001

References in corpus (3)

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• Can the gamma-ray source 3EG J2033+4118 be produced by the stellar system Cyg OB2 No.5?
• Detection of a new, low-brightness supernova remnant possibly associated with EGRET sources

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