The Canada-France Ecliptic Plane Survey—Full Data Release: The Orbital Structure of the Kuiper Belt

We report the orbital distribution of the trans-Neptunian objects (TNOs) discovered during the Canada-France Ecliptic Plane Survey (CFEPS), whose discovery phase ran from early 2003 until early 2007. The follow-up observations started just after the first discoveries and extended until late 2009. We obtained characterized observations of 321 deg² of sky to depths in the range g ~ 23.5-24.4 AB mag. We provide a database of 169 TNOs with high-precision dynamical classification and known discovery efficiency. Using this database, we find that the classical belt is a complex region with sub-structures that go beyond the usual splitting of inner (interior to 3:2 mean-motion resonance [MMR]), main (between 3:2 and 2:1 MMR), and outer (exterior to 2:1 MMR). The main classical belt (a = 40-47 AU) needs to be modeled with at least three components: the "hot" component with a wide inclination distribution and two "cold" components (stirred and kernel) with much narrower inclination distributions. The hot component must have a significantly shallower absolute magnitude (H_g ) distribution than the other two components. With 95% confidence, there are 8000⁺¹⁸⁰⁰ _-1600 objects in the main belt with H_g <= 8.0, of which 50% are from the hot component, 40% from the stirred component, and 10% from the kernel; the hot component's fraction drops rapidly with increasing H_g . Because of this, the apparent population fractions depend on the depth and ecliptic latitude of a trans-Neptunian survey. The stirred and kernel components are limited to only a portion of the main belt, while we find that the hot component is consistent with a smooth extension throughout the inner, main, and outer regions of the classical belt; in fact, the inner and outer belts are consistent with containing only hot-component objects. The H_g <= 8.0 TNO population estimates are 400 for the inner belt and 10,000 for the outer belt to within a factor of two (95% confidence). We show how the CFEPS Survey Simulator can be used to compare a cosmogonic model for the orbital element distribution to the real Kuiper Belt.

Based on observations obtained with MegaPrime/MegaCam, a joint project of the Canada-France-Hawaii Telescope (CFHT) and CEA/DAPNIA, at CFHT which is operated by the National Research Council (NRC) of Canada, the Institute National des Sciences de l'Universe of the Centre National de la Recherche Scientifique (CNRS) of France, and the University of Hawaii. This work is based in part on data products produced at the Canadian Astronomy Data Centre as part of the CFHT Legacy Survey, a collaborative project of NRC and CNRS.