AGN and black hole physics of EHT targets with line interferometry

• Grant number: 25/16561-9
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: September 01, 2025
• End date: August 31, 2029
• Field of knowledge: Physical Sciences and Mathematics - Astronomy - Extragalactic Astrophysics
• Principal Investigator: Ciriaco Goddi
• Grantee: Raphael Pereira Rolim e Silva
• Host Institution: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 21/01183-8 - Astrophysical jets at the highest-angular resolution with very long baseline interferometry, AP.JP

Abstract

Understanding the formation and collimation of relativistic jets in active galactic nuclei (AGN) remains one of the central challenges in high-energy astrophysics. This PhD project aims to probe the immediate environments of supermassive black holes (SMBHs) through high-resolution radio interferometry, combining state-of-the-art observations from the Event Horizon Telescope (EHT), the Global Millimeter VLBI Array (GMVA), and the Atacama Large Millimeter/submillimeter Array (ALMA). The project will address open questions about jet launching mechanisms, the role of magnetic fields and accretion processes, and the influence of molecular and dusty tori surrounding SMBHs.The research will focus on two complementary lines of investigation: (1) imaging the base of relativistic jets in AGN at microarcsecond scales using continuum and polarimetric VLBI observations; and (2) developing new capabilities for spectral line VLBI, enabling the first-ever studies of molecular absorption and emission lines at mm wavelengths and ultra-high angular resolution. These studies will be applied to sources such as Sgr A* and a broader AGN sample, with the goal of characterizing molecular cloud kinematics and the structure of AGN tori.The student will acquire expertise in VLBI calibration and imaging using the CASA-based rPICARD pipeline and will contribute to its extension for spectral line data. Synthetic VLBI observations will be simulated using SYMBA to evaluate the impact of adding the LLAMA observatory to global mm-VLBI networks. By combining data analysis, software development, and observational campaigns, this project will place the student at the forefront of black hole and jet astrophysics and prepare them for a competitive career in radio astronomy.