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

Abstract

7We 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 sq.deg. 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 1 Based on observations obtained with MegaPrime/MegaCam, a joint project of CFHT and CEA/DAPNIA, at the Canada-France-Hawaii Telescope (CFHT) which is operated by the 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 transneptunian 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 the orbital element distribution to the real Kuiper belt. Subject headings: Kuiper Belt, surveys; PACS 96.30.Xa 8 9 42 non-resonant, non-scattering part of the belt beyond the 2:1 MMR with Neptune. Section 6 gives an order 43 of magntitude estimate of the scattering disk's population. Section 7 demonstrates the use of our Survey 44 -4 -Simulator to compare the results of a cosmogonic model to the CFEPS detections. Finally in Section 8, we 45 present our conclusions and put our findings in perspective. 46 2. Observations and Initial reductions 47 The discovery component of the CFEPS project imaged ∼320 square degrees of sky, almost all of 48 which was within a few degrees of the ecliptic plane. Discovery observations occurred in blocks of ≈ 16 49 fields acquired using the Canada-France-Hawaii Telescope (CFHT) MegaPrime camera which delivered ...

The Curiously Warped Mean Plane of the Kuiper Belt

“…In previous studies (e.g., Brown 2001; Gulbis et al 2010;Petit et al 2011;Gladman et al 2012), this functional form for the inclination distribution has been used to model the intrinsic inclination distribution of the Kuiper Belt, and different values of the Gaussian standard deviation, σ, have been derived for different dynamical classes of KBOs. We note, however, that the intrinsic distribution of Ω will not actually be uniformly random if the population's mean plane deviates from the chosen reference plane.…”

“…With the methods described in the previous section, we find that the mean plane of this population has J2000 ecliptic-equinox inclination and longitude of ascending node i 1 . 8 Gulbis et al 2010;Petit et al 2011Petit et al , 2017. We generated 40,000 simulated sets of 769 objects with the same semimajor axes as the real classical KBOs.…”

“…For the Monte Carlo simulations, we assumed that the intrinsic inclinations (relative to each prescribed mean plane) are drawn from a Rayleigh distribution of i sin with parameter sin 18 s = . This choice is consistent with observational constraints of this population's inclination dispersion (e.g., Gulbis et al 2010;Petit et al 2011), and it yields synthetic data sets with ecliptic inclination and longitude of ascending node distributions that are not rejected at a 95% confidence level when an Anderson-Darling test is used to compare them to the observed population's inclination and node distributions. We discuss other possible choices for the inclination distribution later in this section.…”

“…The observationally derived widths of the KBOs' inclination distribution function have been used as constraints on theoretical models of the dynamical excitation history of the outer solar system (e.g., Gomes 2003;Nesvorný 2015). In the literature, the measures of the effective width of the inclination distribution function are based on KBOs' inclinations relative to the ecliptic plane (e.g., Brown 2001), invariable plane (e.g., Petit et al 2011), or mean plane of the entire Kuiper Belt (usually assumed to be consistent with the invariable plane, e.g., Elliot et al 2005;Gulbis et al 2010). However, the most dynamically meaningful measure of the effective width of the inclination distribution will be that measured for inclinations relative to the local forced plane.…”

Impacts of Cosmic Dust on Planetary Atmospheres and Surfaces

“…Between 10 and 30 AU, OCC dust is predicted to be dominant, with some additional contributions (∼10-20%) from both JFC and EKB dust. Finally, at distances greater than 30 AU the EKB dust dominates, reflecting the near-by location of the EKB parent bodies themselves (e.g., Petit et al 2011). One can also see the very large discrepancy between the extrapolated Grün et al (1985) model prediction and the total flux found in Poppe (2016), with the latter typically an order-of-magnitude less than the former.…”