Abstract We extend the work of Roychowdhury on skewness variations of the logarithmic flux, driven by large GeV flares in flat spectrum radio quasars (FSRQs), to a sample of 18 FSRQs. We find that they can be categorized into three groups, one where the skewness attains a persistent lower value after a large flare, one where it increases, and those where a change in skewness is not significant. To provide a theoretical ground for these results, we use the statistical plasmoid model of R. L. Fermo et al. (2010) that self-consistently produces large plasmoids through merging, which, when they gain energy from the reconnection event and are Doppler aligned, produce large flares. We find that a downsampling of our simulation of 1500 runs to 18 statistically reproduces the observed distribution in p -values for a change in skewness. We further compute the ensemble Shannon entropy of the system and the skewness, where the entropy is found to decrease at a 3 σ level in both the groups where skewness either increases or decreases, as a direct evidence of an increase in the order in the system caused by a flare. We find that the power spectral densities of the simulated light curves are broken power laws, resembling a white noise+red noise broken by the typical cooling timescale in our system, in accordance with known blazar variability. We find that our results are robust to a 200%–300% change in several fiducial parameters of the simulation. Our stochastic simulation of plasmoids inside a blazar jet is consistent with key observable statistical properties of blazar GeV light curves.
Agniva Roychowdhury (Wed,) studied this question.