Studies of Physical and Radiative Processes around Black Holes with Magnetohydrodynamical Simulations and Artificial Intelligence: Preparing for the Cherenkov Telescope Array and the ASTRI Mini-Array

• Grant number: 24/05459-6
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: July 01, 2024
• End date: March 31, 2028
• Field of knowledge: Physical Sciences and Mathematics - Astronomy - Extragalactic Astrophysics
• Principal Investigator: Elisabete Maria de Gouveia Dal Pino
• Grantee: Luana Passos Reis
• Host Institution: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 21/02120-0 - Investigation of high energy and plasma astrophysics phenomena, installation of the ASTRI-Mini Array & construction of the Cherenkov Telescope Array Small Size Telescopes (CTA-SSTs), AP.ESP

Abstract

This PhD project aims at the investigation of magnetohydrodynamic processes in the extremely energetic environments of supermassive black hole (BH) accretion disks and jets, with a focus on unraveling their correlation with the generation of very high energy (VHE) cosmic rays (exceeding 10^15 eV) and subsequent emissions. The energetic particles involved experience radiative losses through interactions with magnetic and photon fields. Particularly significant are the non-thermal emissions, notably in gamma rays and neutrinos, which bear crucial signatures of the plasma phenomena surrounding BHs. Recent efforts combining theoretical frameworks, numerical simulations, and observational data have initiated an understanding of the underlying physical mechanisms in these environments, addressing key enigmas such as the origins of ultra-high-energy cosmic rays (UHECRs) and the VHE gamma-ray flares they provoke. In the inner regions, these systems are dominated by magnetic fields and Fermi-like particle acceleration driven by magnetic reconnection is expected to be prevalent. This PhD project aims to build upon recent advancements in this domain conducted by our research group. Key objectives include: (i) performing relativistic magnetohydrodynamics (RMHD) simulations of jets and accretion flows around BHs; (ii) use these simulations as the background plasma to investigate the generation of VHE gamma-rays and neutrinos by cosmic rays (CRs), particularly within AGN blazars, the most prolific gamma-ray emitters. This involves employing a Monte Carlo approach for CR propagation and employing artificial intelligence (AI) with population-based metaheuristic algorithms to model their leptonic-hadronic spectral energy density (SED) across a wide parameter space; and (iii) undertaking statistical analyses on data from the Fourth Catalog of Active Galactic Nuclei detected by the Fermi Large Area Telescope (4LAC Catalog), discerning variability patterns and extrapolating them to the VHE gamma-ray spectrum to generate synthetic SEDs and light curves for selected AGNs, thereby facilitating predictions for forthcoming facilities like the Cherenkov Telescope Array (CTA) and ASTRI Mini-Array. The advancements in sensitivity and resolution of Cherenkov instruments with these new facilities will enable unprecedented gamma-ray measurements of numerous compact objects, enhancing our comprehension of the physics and radiation emanating from these sources.