Searching for Possible Correlations of γ-Ray and X-Ray Emissions from Active Galactic Nuclei

Thomas Graham Spears

The Discrete Correlation Function (DCF) was used to correlate X-ray and γ-ray light curves for the BL Lac object 3C279. Rigorous testing was performed on the DCF to understand how it responds to perturbations in its parameters, such as varying the bin size. A flux randomization technique was utilized to calculate experimental errors in addition to the statistical errors generated by the DCF. RXTE and EGRET data for the early 1996 flare was used in this analysis. Through testing the DCF and using the flux randomization procedure, results were generated that are consistent with earlier work. However, mathematically these correlations are not as strong as one might have expected from a visual inspection of the light curves. This indicates that the discriminating power of the DCF for X-ray and γ-ray data may not be as robust as has previously been assumed.