The size distribution of trans-Neptunian bodies

Abstract

The magnitude distribution of the trans-Neptunian bodies composed of the Kuiper Belt Objects (KBOs) and Scattered Disk Objects (SDOs) is determined for absolute magnitudes H ⩽ 7 , using maximum likelihood estimation methods. This is translated into a corresponding size distribution. This gave a differential size index of q = 3.966 ± 0.15 for KBOs and q = 3.016 ± 0.32 for SDOs. It was found that these two distributions were statistically different. The KBOs were further split into classical KBOs and Plutinos which had indices of q = 4.074 ± 0.18 and q = 3.301 ± 0.37 , respectively. There was no statistical evidence that these are different populations. The classical KBOs were further split and examined for four different semi-major axis ranges and it was found that there was moderate evidence that the entire sample was not well represented by one index. The distribution indices of the SDOs were compared with the distributions of short period comets and found to be similar. It is likely that the scattered disk population is the source of the short period comets.