Despite the low level of current activity in the Galactic centre, X-ray reflection from molecular clouds in the Sgr A* region seem to imply that the supermassive black hole was orders of magnitude brighter just a few hundred years ago than it is currently. We investigate the idea of the Galactic centre minispiral as the origin of gaseous material for the enhanced past activity of Sgr A*.
Collisions between clumps of gas in the minispiral can reduce their angular momentum and set some of the clumps on a plunging trajectory towards the supermassive black hole. We demonstrate that the amount of material contained in the minispiral is sufficient to sustain the luminosity of Sgr A* at the required level. We also study the possibility of the formation of thermal instability in the two-phase minispiral region, enhancing the accretion of clouds by the central black hole.