SEMINÁRIO DO DEPARTAMENTO DE ASTRONOMIA
Studying black holes on event horizon-scales
a talk by Ziri Younsi (University College London, UK) - In-Person
Abstract:
Multimessenger astrophysics has emerged as a powerful approach to understanding the universe through the combined detection of different cosmic messengers, including high-energy photons, cosmic rays, neutrinos, and gravitational waves. This new paradigm allows for a deeper exploration of astrophysical phenomena, unveiling the nature of some of the most energetic and mysterious processes in the cosmos. In this talk, I will discuss the role of two major observatories in advancing multimessenger studies: the Cherenkov Telescope Array Observatory (CTAO) and the Pierre Auger Observatory. The CTAO, a next-generation observatory, will be the most sensitive facility for detecting very-high-energy gamma rays. With its unprecedented sensitivity and large field of view, CTAO is expected to play a crucial role in identifying the sources of high-energy gamma rays and exploring their connection to other cosmic messengers, such as neutrinos and cosmic rays. It will provide insights into extreme astrophysical environments, like supernova remnants, active galactic nuclei, and starburst regions. The Pierre Auger Observatory, located in Argentina, is the world's largest cosmic ray detector, dedicated to studying the highest-energy particles that reach Earth. Auger's ability to detect ultra-high-energy cosmic rays (UHECRs) has enabled significant advances in understanding their origins, propagation, and interaction with cosmic backgrounds. The recent upgrades to the Auger Observatory have enhanced its capacity to identify the nature of primary particles, contributing to a more precise determination of their sources. In this presentation, I will explore how the synergy between CTAO and Auger, alongside other multimessenger observatories, enhances our understanding of cosmic accelerators and the astrophysical processes at play. By combining gamma-ray observations from CTAO with the ultra-high-energy cosmic ray data from Auger, we can better constrain source models, probe particle acceleration mechanisms, and address fundamental questions about the nature of the high-energy universe. One example to be explored is the search for Lorentz Invariance Violation. This collaborative approach exemplifies the power of multimessenger astrophysics to push the boundaries of our knowledge and reveal the hidden dynamics of the most extreme events in the universe
Short-Bio:
Dr. Ziri Younsi is a UKRI Stephen Hawking Fellow and Assistant Professor at University College London (UCL), Mullard Space Science Laboratory. He co-leads the Event Horizon Telescope (EHT) Collaboration's gravitational physics working group, previously serving on the project's science council. He has developed numerical codes for simulating and interpreting the first image of a black hole. His research into black hole images in different theories of gravity enabled the first constraints on the spacetime geometry of our Milky Way black hole. Ziri graduated in Mathematics from the University of Cambridge, with his Physics MSc and Astrophysics PhD from UCL. He is also a keen science communicator, addressing learned societies, science festivals, media outlets, private industry, and the UK Government.
Google Meet: https://meet.google.com/pcw-gmem-jyi
Link da transmissão: https://www.youtube.com/c/AstronomiaIAGUSP/live