Radiative model reconstruction of the Galactic Center central gamma-ray source

• Ano de defesa: 2024
• Autor(a) principal: Momesso, Daniel Cecchin
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: Acceleration of particles; Aceleração de partículas; Astronomia de raios gama; Centro Galáctico; Galactic Center; Gamma-ray astronomy
• Link de acesso: https://www.teses.usp.br/teses/disponiveis/76/76134/tde-22112024-092557/

Among all the high-energy environments in our Galaxy, the Galactic Center region stands out as a unique cosmic laboratory. The high stellar density, the presence of a supermassive black hole, and the intense magnetic activity in this area create ideal conditions for the acceleration of particles to extreme energies. In this context, the Galactic Center hosts the brightest gamma-ray source, known as HESS J1745-290. However, the mechanism responsible for its gamma-ray emission remains unknown. In light of this, this dissertation aims to investigate the possibility that the source HESS J1745-290 is associated with a PeVatron identified in this region. To investigate this hypothesis, we modeled the molecular clouds located within the central 10 parsecs of the supermassive black hole Sgr A*. Subsequently, we calculated the gamma-ray flux resulting from the decay of neutral pions (π0), which occurs during the proton-proton interactions of cosmic rays colliding with the molecular clouds in the diffusion process. This calculation was performed for two distinct regimes of the source term: the impulsive case and the continuous case, which would be observed by the H.E.S.S. and CTA telescopes. From a spatial analysis, we extracted parameters related to the centroid position and the source extension, with the aim of comparing these results with those obtained by the H.E.S.S. Collaboration, thereby inferring which gamma-ray emissivity scenario is occurring in this region.