CFHT UM2025 - Presentation Details
Abstract Details
Title: OSSOS: Outer Solar System Origin Survey - a high-impact LP
Presenter: Jean-marc Petit
Abstract:
The OSSOS Large Program was allocated 560 hours of observing on MegaPrime between 2013A and 2016B. As of spring 2025, this survey of the Kuiper belt has resulted in 36 publications cited 1065 times. This multi-year project’s substantial impact in understanding the formation and evolution of the outer solar system was made possible by the LP’s focused observational effort and adherence to the needed observational cadence for solar system science enabled by the QSO model. A model of the intrinsic orbital and size distributions of the Kuiper belt is highly valuable for many situations, including observation planning, observation interpretation, and model interpretation. The Kuiper belt consists of several orbital sub-populations: the resonant TNOs, the hot and cold main classical belt, the outer/detached belt, the scattering objects, and the inner main belt. These sub-populations have two distinct size distributions: one for the cold-classical region and a size distribution for the hot sub-populations. The Outer Solar System Origins Survey (OSSOS) has assembled several well-characterized observational efforts, all with CFHT MegaCam (collectively referred to as the OSSOS sample), to provide a comprehensive determination of the orbital and size-distribution properties of various components of the Kuiper belt. In this presentation, I will highlight some remarkable results which were made possible by OSSOS, with an emphasis on the orbital and size-distribution modeling of the outer solar system. For the first time, we have been able to bridge the gap between observed size-distribution and the outcome from the currently preferred formation model via streaming and gravitational instability. Our OSSOS Kuiper belt model is the amalgamation of the various sub-components of the Kuiper belt (each published separately to date). This combined model provides a good representation of the orbital distributions and actual populations of the Kuiper belt, measured using statistical comparisons between actual observations and the forward-biased model from the OSSOS Survey Simulator. This presentation will provide the background needed to understand how the OSSOS model was created, and I will give some examples of how that model has been and can be used.