Heidelberg 2022 – wissenschaftliches Programm

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EP: Fachverband Extraterrestrische Physik

EP 7: Astrophysics

EP 7.4: Vortrag

Mittwoch, 23. März 2022, 17:00–17:15, EP-H1

Analytic examination of AGN variability in a two-zone model — •Vito Aberham and Felix Spanier — Institut für Theoretische Astrophysik, Albert-Ueberle-Straße 2, 69120 Heidelberg

The variability of active galactic nuclei is examined analytically using a two-zone model that injects particles in a monoenergetic fashion. The elemental PDEs of both zones are solved neglecting terms behaving as second-order Fermi acceleration. The time-dependent behavior of the obtained particle distributions is inspected by employing a variable source function. As time approaches infinity the steady state distribution functions are recovered displaying the expected spectral indices. Being typical for BL Lac objects parameter estimates from a model fitting the SED of the blazar TXS 0506+056 are incorporated. Corresponding photon and neutrino fluxes in both local jet and earth frame are determined and compared to observations. The general time-dependence of photon light curves in various bands and the neutrino flux is evaluated by implementing a time-dependent initial source function. The variability timescales of relevant quantities are ultimately inferred also considering the effect of different particle species. It is demonstrated how the analytical results can be utilized to cross-check results from numerical simulation as well as to interpret observational data collected at different times.