Multiwavelength variability of quasar 3C 273 described by nonextensive statistical mechanics

Abstract We investigate whether the multiwavelength variability of quasar 3C 273 can be described in terms of nonextensive statistical mechanics. Using a dataset of 39 light curves spanning from radio to X-rays collected by the Integral Science Data Centre (ISDC) database, we apply the q -Gaussian formalism to determine the entropic index q for each spectral band. Our analysis reveals a nontrivial dependence of q on energy, with two prominent increases from radio to mm/submm and hard X-ray domains. The first linear trend is likely associated with synchrotron flares and thermal emission from hot dust, while the second may reflect inverse Compton processes in a turbulent jet environment. However, the second linear trend in the hard X-ray range lacks statistical robustness due to limited data or large measurement uncertainties. Interestingly, the q values show no clear correlation with the fractional variability amplitude , suggesting that q captures a different aspect of the source's dynamical behavior. These findings offer new insights into how different emission mechanisms and physical regions in AGNs may manifest distinct degrees of statistical complexity.