Semi-major axis histogram under the presence of all planets for β = 0.1, 0.05, 0.03, 0.01, 0.005 (D = 5 μm, 10 μm, 17 μm, 50 μm, 100 μm) from top to bottom. Occupancy is the number of particles per 0.0005 au bin divided by solar distance of that bin and then normalised to background count (i.e. under the absence of resonances). Vertical dashed lines indicate the locations of several first order as well as the co-orbital MMRs (including a shifting factor to account for radiation pressure).