Very-high-energy Emission from Magnetic Reconnection in the Radiative-inefficient Accretion Flow of SgrA*

Autor(es)

Rodriguez-Ramirez, Juan Carlos ; de Gouveia Dal Pino, Elisabete M. ; Batista, Rafael Alves

• Tipo de documento: Artigo Científico
• Fonte: ASTROPHYSICAL JOURNAL; v. 879, n. 1, p. 10-pg., 2019-07-01.

Resumo

The cosmic-ray (CR) accelerator at the Galactic center (GC) is not yet established by current observations. Here we investigate the radiative-inefficient accretion flow (RIAF) of Sagittarius A* (SgrA*) as a CR accelerator assuming acceleration by turbulent magnetic reconnection, and derive possible emission fluxes of CRs interacting within the RIAF (the central similar to 10(13) cm). The target environment of the RIAF is modeled with numerical, general relativistic magnetohydrodynamics together with leptonic radiative transfer simulations. The acceleration of the CRs is not computed here. Instead, we inject CRs constrained by the magnetic reconnection power of the accretion flow and compute the emission/absorption of gamma-rays due to these CRs interacting with the RIAF, through Monte Carlo simulations employing the CRPropa 3 code. The resulting very-high-energy (VHE) fluxes are not expected to reproduce the point source HESS J1745-290 as the emission of this source is most likely produced at parsec scales. The emission profiles derived here intend to trace the VHE signatures of the RIAF as a CR accelerator and provide predictions for observations of the GC with improved angular resolution and differential flux sensitivity as those of the forthcoming Cerenkov Telescope Array (CTA). Within the scenario presented here, we find that for mass accretion rates greater than or similar to 10(-7) M(circle dot)yr(-1), the RIAF of SgrA* produces VHE fluxes that are consistent with the High Energy Stereoscopic System (H.E.S.S.) upper limits for the GC and potentially observable by the future CTA. The associated neutrino fluxes are negligible compared with the diffuse neutrino emission measured by the IceCube. (AU)

• Processo FAPESP: 17/12188-5 - Estudo de partículas relativísticas e emissões de alta energia em torno de fontes de buracos negros e jatos por meio de simulações MHD, partículas-em-células (PIC) e transferência radiativa
• Beneficiário: Juan Carlos Rodríguez Ramírez
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 13/10559-5 - Investigação de fenômenos de altas energias e plasmas astrofísicos: teoria, simulações numéricas, observações e desenvolvimento de instrumentação para o Cherenkov Telescope Array (CTA)
• Beneficiário: Elisabete Maria de Gouveia Dal Pino
• Modalidade de apoio: Auxílio à Pesquisa - Projetos Especiais
• Processo FAPESP: 17/12828-4 - Difusão, aceleração e propagação de raios cósmicos em ambientes astrofísicos turbulentos
• Beneficiário: Rafael Alves Batista
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 09/54006-4 - Um cluster de computadores para o Departamento de Astronomia do IAG-USP e para o Núcleo de Astrofísica da UNICSUL
• Beneficiário: Elisabete Maria de Gouveia Dal Pino
• Modalidade de apoio: Auxílio à Pesquisa - Programa Equipamentos Multiusuários