OSSOS. XXIX. The Population and Perihelion Distribution of the Detached Kuiper Belt

Abstract

The detached trans-Neptunian objects (TNOs) are those with semimajor axes beyond the 2:1 resonance with Neptune that are neither resonant nor scattering. Using the detached sample from the Outer Solar System Origins Survey (OSSOS) telescopic survey, we produce the first studies of their orbital distribution based on matching the orbits and numbers of the known TNOs after accounting for survey biases. We show that the detached TNO perihelion ( q ) distribution cannot be uniform but is instead better matched by two uniform components with a break near q ≈ 40 au. We produce parametric two-component models that are not rejectable by the OSSOS data set and estimate that there are 36,000 ${}_{-9000}^{+12,000}$ detached TNOs with absolute magnitudes H _r 50 au objects are likely present, we conclude that there are (5 ± 2) × 10 ^4 dynamically detached TNOs, roughly twice as many as in the entire trans-Neptunian hot main belt.

Keywords

• Detached objects
• Trans-Neptunian objects
• Small Solar System bodies
• Kuiper belt