Unraveling the particle dynamics in Active Galactic Nuclei via multi wavelength photometry and polarimetry of bright blazars (Axel Arbet-Engels, Max Planck Institute for Physics)

Monday Dec 9, 2024, 2:00 PM → 4:00 PM Europe/Paris

amphi Charpak

Active Galactic Nuclei (AGNs) are among the most powerful persistent particle accelerators in our universe. Despite decades of investigations, AGNs are still far from being understood. Because they are prime candidate sources of ultra-high-energy cosmic rays and high-energy neutrinos, their understanding is key in the current era of multi-messenger astronomy. The advent of new instrumentation for photon and neutrino astronomy brings new scientific capabilities to probe the underlying physics of these cosmic accelerators. Among all AGNs, the best candidates to probe the evolution of the particle distribution are blazars that are nearby and bright throughout the electromagnetic spectrum. I will summarize the current knowledge of AGN physics and present recent results from our multiwavelength programs of nearby AGNs making use, for the first time, of X-ray polarisation thanks to the IXPE satellite. I will discuss how such results provide powerful insights on the acceleration process, even if a high degree of complexity is revealed. The next step is to validate theoretical models (and the related dynamics) with dedicated simulations for particle acceleration and temporal evolution. 

blazars_lpnhe_seminar.pdf