General relativistic MHD simulations of non-thermal flaring in
  Sagittarius A*
  Sagittarius A* exhibits regular variability in its multiwavelength emission,
including daily X-ray flares and roughly continuous near-infrared (NIR)
flickering. The origin of this variability is still ambiguous since both
inverse Compton and synchrotron emission are possible radiative mechanisms. The
underlying particle distributions are also not well constrained, particularly
the non-thermal contribution. In this work, we employ the GPU-accelerated
general relativistic magnetohydrodynamics (GRMHD) code H-AMR perform a study of
flare flux distributions, including the effect of particle acceleration for the
first time in high-resolution 3D simulations of Sgr A*. For the particle
acceleration, we use the general relativistic ray-tracing (GRRT) code BHOSS to
perform the radiative transfer, assuming a hybrid thermal+non-thermal electron
energy distribution. We extract ~60 h lightcurves in the sub-millimetre, NIR
and X-ray wavebands, and compare the power spectra and the cumulative flux
distributions of the lightcurves to statistical descriptions for Sgr A* flares.
Our results indicate that non-thermal populations of electrons arising from
turbulence-driven reconnection in weakly magnetised accretion flows lead to
moderate NIR and X-ray flares and reasonably describe the X-ray flux
distribution while fulfilling multiwavelength flux constraints. These models
exhibit high rms% amplitudes, >~150% both in the NIR and the X-rays, with
changes in the accretion rate driving the 230~GHz flux variability, in
agreement with Sgr A* observations.
