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

Abstract

The detached transneptunian objects (TNOs) are those with semimajor axes beyond the 2:1 resonance with Neptune, which are neither resonant nor scattering. Using the detached sample from the 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 $q\approx 40$ au. We produce parametric two-component models that are not rejectable by the OSSOS data set, and estimate that there are $36,000_{-9,000}^{+12,000}$ detached TNOs with absolute magnitudes $H_r<8.66$ ($D\gtrsim 100$ km) and semimajor axes $48<a<250$ au (95% confidence limits). Although we believe these heuristic two-parameter models yield a correct population estimate, we then use the same methods to show that the perihelion distribution of a detached disk created by a simulated rogue planet matches the $q$ distribution even better, suggesting that the temporary presence of other planets in the early Solar System is a promising model to create today's large semimajor axis TNO population. This numerical model results in a detached TNO population estimate of $48,000_{-12,000}^{+15,000}$. Because this illustrates how difficult-to-detect $q>50$ au objects are likely present, we conclude that there are $(5\pm 2)\times 10^4$ dynamically detached TNOs, which are thus roughly twice as numerous as the entire transneptunian hot main belt.

Accepted for publication in The Planetary Science Journal. 16 pages, 8 figures

References in corpus (13)

• The Planet Nine Hypothesis
• Tracking Neptune's Migration History through High-Perihelion Resonant Trans-Neptunian Objects
• A Possible Divot in the Size Distribution of the Kuiper Belt's Scattering Objects
• A search of the full six years of the Dark Energy Survey for outer Solar System objects
• Reassessing the formation of the Inner Oort cloud in an embedded star cluster II: Probing the inner edge
• The orbital distribution of trans-Neptunian objects beyond 50 au
• Producing Distant Planets by Mutual Scattering of Planetary Embryos
• Dynamical Classification of Trans-Neptunian Objects Detected by the Dark Energy Survey
• Resonant Kuiper Belt Objects -- a Review
• A Rogue Planet Helps Populate the Distant Kuiper Belt
• OSSOS XVIII: Constraining migration models with the 2:1 resonance using the Outer Solar System Origins Survey
• Details of Resonant Structures Within a Nice Model Kuiper Belt: Predictions for High-Perihelion TNO Detections
• The Stability Boundary of the Distant Scattered Disk

Cited by in corpus (3)

• Predictions of the LSST Solar System Yield: Near-Earth Objects, Main Belt Asteroids, Jupiter Trojans, and Trans-Neptunian Objects
• Dynamics of Binary Planets within Star Clusters
• Early Stellar Flybys are Unlikely: Improved Constraints from Sednoids and Large-$q$ TNOs