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

¹ Departamento de Física, Universidade Federal do Ceará - Caixa Postal 6030, Campus do Pici, 60455-900 Fortaleza, Ceará, Brazil
² Avignon Université, Campus Jean-Henri Fabre, Centre d'Enseignement et de Recherche en Informatique Agroparc, BP 91228, 84911 Avignon Cedex 9, France

Received: 13 October 2025
Accepted: 9 February 2026

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.