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Sgr A* exhibits flares in the near-infrared and X-ray bands, with theluminosity in these bands increasing by factors of $10-100$ for $\approx 60$minutes. One of the models proposed to explain these flares is synchrotronemission of non-thermal particles accelerated by magnetic reconnection eventsin the accretion flow. We use the results from PIC simulations of magneticreconnection to post-process 3D two-temperature GRMHD simulations of amagnetically arrested disc (MAD). We identify current sheets, retrieve theirproperties, estimate their potential to accelerate non-thermal particles andcompute the expected non-thermal synchrotron emission. We find that the fluxeruptions of MADs can provide suitable conditions for accelerating non-thermalparticles to energies $\gamma_e \lesssim 10^6$ and producing simultaneous X-rayand near-infrared flares. For a suitable choice of current-sheet parameters anda simpified synchrotron cooling prescription, the model can simultaneouslyreproduce the quiescent and flaring X-ray luminosities as well as the X-rayspectral shape. While the near-infrared flares are mainly due to an increase inthe temperature near the black hole during the MAD flux eruptions, the X-rayemission comes from narrow current sheets bordering highly magnetized,low-density regions near the black hole and equatorial current sheets where theflux on the black hole reconnects. As a result, not all infrared flares areaccompanied by X-ray ones. The non-thermal flaring emission can extend to veryhard ($\lesssim 100$ keV) X-ray energies.

Sgr A* X-ray flares from non-thermal particle acceleration in a magnetically arrested disc