Seminar: Giacomo Principe - Multi-messenger exploration of super-massive black holes and jets

Speaker: Giacomo Principe, INAF, Italy

Title: Multi-messenger exploration of super-massive black holes and jets

Abstract

Supermassive black holes (SMBHs) at the centers of galaxies are among the most powerful engines in the universe, driving activity across the entire electromagnetic spectrum and beyond. Yet, despite decades of study, many fundamental questions remain unanswered: How are relativistic jets launched and collimated? Where and how are gamma rays produced in active galactic nuclei (AGNs)? Are AGNs viable sources of high-energy neutrinos? Do they emit low-frequency gravitational waves, and which systems are the most promising targets for their detection via pulsar timing arrays (PTAs)?

In this seminar, I will present recent developments in our understanding of SMBHs through a multi-messenger perspective, combining high-resolution Event Horizon Telescope (EHT) radio imaging with multi-wavelength (MWL) observations—ranging from radio to very-high-energy gamma rays — as well as data from high-energy neutrino and gravitational wave detectors. Through this synergistic approach, I will offer new insights into the nature of SMBHs, with a particular focus on key EHT targets such as Sgr A*, M87, and 3C 279 — prototypical examples of a quiescent black hole, radio galaxy, and blazar, respectively.

These findings aim to contribute to the rapidly evolving field of multi-messenger astrophysics by exploring the above open questions and by helping to bridge high-energy particles, electromagnetic observations, and gravitational wave searches within a unified framework.