| Full text | |
| Author(s): |
Rodriguez-Ramirez, Juan Carlos
;
de Gouveia Dal Pino, Elisabete M.
;
Batista, Rafael Alves
Total Authors: 3
|
| Document type: | Journal article |
| Source: | ASTROPHYSICAL JOURNAL; v. 879, n. 1, p. 10-pg., 2019-07-01. |
| Abstract | |
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) | |
| FAPESP's process: | 17/12188-5 - Study of relativistic particles and high energy emissions around black hole and jet sources through MHD, particle-in-cell (PIC) and radiative transfer |
| Grantee: | Juan Carlos Rodríguez Ramírez |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |
| FAPESP's process: | 13/10559-5 - Investigation of high energy and plasma astrophysics phenomena: theory, numerical simulations, observations, and instrument development for the Cherenkov Telescope Array (CTA) |
| Grantee: | Elisabete Maria de Gouveia Dal Pino |
| Support Opportunities: | Special Projects |
| FAPESP's process: | 17/12828-4 - Diffusion, acceleration and propagation of cosmic rays in turbulent astrophysical environments |
| Grantee: | Rafael Alves Batista |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |
| FAPESP's process: | 09/54006-4 - A computer cluster for the Astronomy Department of the University of São Paulo Institute of Astronomy, Geophysics and Atmospheric Sciences and for the Cruzeiro do Sul University Astrophysics Center |
| Grantee: | Elisabete Maria de Gouveia Dal Pino |
| Support Opportunities: | Multi-user Equipment Program |