Variability time scales in the gamma-ray blazars using structure function analysis

About 50 active galactic nuclei (AGN) have been detected by the Energetic Gamma Ray Experiment Telescope (EGRET) on board the Compton Gamma Ray Observatory since its launch in 1991. A majority of them are Rat spectrum quasars and a few of them are BL Lacertae (BL Lac) objects. Some of the current models predict different time scales for variability in various regions of the electro-magnetic spectrum. Using structure function analysis, we are examining the variability time-scales in a few of the sources in the gamma-ray region. The existence of a maximum time-scale of correlation is being investigated in each source, The possible existence of multiple time-scales in single sources is also being explored. We present the preliminary results of an analysis of data on 3C279 in the 100 MeV-10000 MeV region.