Scheme of the different “buckets” that can hold tracer particles and the process that moves them around. The three buckets are gas cells, stars, and SMBHs. Arrows indicate outgoing mass fluxes between buckets and the physical process associated, and grey squares represent tracer particles. The jet mode feedback from AGNs (around SMBHs) is able to move gas tracer particles from the central cell to the surrounding cells. The particles have no spatial distribution within the buckets or any phase-space distribution. Tracer particles are exchanged probabilistically between buckets based on the mass fluxes. For example, for the gas, they are exchanged based on the mass fluxes at the boundary of the cells.