VHE Emission from Magnetic Reconnection in the RIAF of SgrA*. (arXiv:1904.05765v1 [astro-ph.HE])
<a href="http://arxiv.org/find/astro-ph/1/au:+Rodrigurez_Ramirez_J/0/1/0/all/0/1">Juan Carlos Rodrígurez-Ramírez</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pino_E/0/1/0/all/0/1">Elisabete M. de Gouveia Dal Pino</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Batista_R/0/1/0/all/0/1">Rafael Alves Batista</a>
Current observations are not able to directly determine the CR accelerator at
the galactic centre (GC). Here we investigate VHE hadronic radiation produced
within the radiative-inefficient accretion flow (RIAF) of Sagittarius A*
(SgrA*) considering a scenario where CRs are accelerated by turbulent magnetic
reconnection. We then derive possible emission profiles constrained by the
magnetic reconnection power and produced within the accretion flow zone (the
central $sim10^{13}$ cm). Wether this mechanism contributes to the currently
observed emission of the source HESS J1745-290 near the galactic centre remains
unclear, due to the limited angular resolution of current instruments. Thus,
the emission profiles derived here intend to be predictions for future
observations with improved angular resolution and differential flux
sensitivity. To model the gas density, magnetic field, and soft photon field of
the accretion flow, we consider a numerical, axi-symmetric, general
relativistic (GR) magneto-hydrodynamic (MHD) simulation together with Monte
Carlo leptonic radiative transfer calculations for which we employ the {tt
harm} and {tt grmonty} codes. CRs are assumed to be accelerated by turbulent
magnetic reconnection and we constrain their injection with the magnetic
reconnection power of the accretion flow. The emission and absorbtion of VHE
gamma-rays are simulated with the Monte Carlo {tt CRPropa 3} code. Within the
scenario presented here, we find that for mass accretion rates $gtrsim
10^{-7}$ M$_odot$ yr$^{-1}$, the RIAF of SgrA* is able to produce VHE fluxes
that are consistent with H.E.S.S. upper limits and potentially detectable by
the future CTA. The neutrino fluxes associated to these emission profiles are
negligible compared with the diffuse neutrino emission measured by the IceCube.
Current observations are not able to directly determine the CR accelerator at
the galactic centre (GC). Here we investigate VHE hadronic radiation produced
within the radiative-inefficient accretion flow (RIAF) of Sagittarius A*
(SgrA*) considering a scenario where CRs are accelerated by turbulent magnetic
reconnection. We then derive possible emission profiles constrained by the
magnetic reconnection power and produced within the accretion flow zone (the
central $sim10^{13}$ cm). Wether this mechanism contributes to the currently
observed emission of the source HESS J1745-290 near the galactic centre remains
unclear, due to the limited angular resolution of current instruments. Thus,
the emission profiles derived here intend to be predictions for future
observations with improved angular resolution and differential flux
sensitivity. To model the gas density, magnetic field, and soft photon field of
the accretion flow, we consider a numerical, axi-symmetric, general
relativistic (GR) magneto-hydrodynamic (MHD) simulation together with Monte
Carlo leptonic radiative transfer calculations for which we employ the {tt
harm} and {tt grmonty} codes. CRs are assumed to be accelerated by turbulent
magnetic reconnection and we constrain their injection with the magnetic
reconnection power of the accretion flow. The emission and absorbtion of VHE
gamma-rays are simulated with the Monte Carlo {tt CRPropa 3} code. Within the
scenario presented here, we find that for mass accretion rates $gtrsim
10^{-7}$ M$_odot$ yr$^{-1}$, the RIAF of SgrA* is able to produce VHE fluxes
that are consistent with H.E.S.S. upper limits and potentially detectable by
the future CTA. The neutrino fluxes associated to these emission profiles are
negligible compared with the diffuse neutrino emission measured by the IceCube.
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