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On the time variability of γ ‐ray sources: a numerical analysis of variability indices
Author(s) -
Torres D.F.,
Pessah M.E.,
Romero G.E.
Publication year - 2001
Publication title -
astronomische nachrichten
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.394
H-Index - 63
eISSN - 1521-3994
pISSN - 0004-6337
DOI - 10.1002/1521-3994(200110)322:4<223::aid-asna223>3.0.co;2-k
Subject(s) - physics , astrophysics , latitude , monte carlo method , statistical physics , secular variation , astronomy , statistics , mathematics
We present a Monte Carlo analysis of the recently introduced variability indices τ (Tompkins 1999) and I (Zhang et al. 2000 & Torres et al. 2001) for γ ‐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 σ ). 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.