Testing time variability of gamma-ray flux

TL;DR

This paper presents a method to examine time variability in gamma-ray signals, analyzing the gamma-ray source PKS 2155-304 and identifying significant fluctuations over months and days.

Contribution

It introduces a new approach to test for time variability in gamma-ray signals and applies it to PKS 2155-304, revealing notable flux fluctuations.

Findings

Detected significant gamma-ray flux variations over months and days.

Identified measurements with excesses or deficiencies with high significance.

Provided a framework for testing non-zero gamma-ray signals for time changes.

Abstract

A way of examining a hypothetical non--zero $\gamma$--ray signal for the time changes is presented. The time variability of the recently observed $\gamma$--ray source PKS 2155--304 is discussed. Several measurements were found to be excessive or deficient with large significances on time scales of months and days.