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 ...

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In this work, we construct a new model for the collisional evolution of the main asteroid belt. Our goals are to test the scaling law of Benz and Asphaug (1999) and ascertain if it can be used for the whole belt. We want to find initial size-frequency distributions (SFDs) for the considered six parts of the belt (inner, middle, 'pristine', outer, Cybele zone, high-inclination region) and to verify if the number of synthetic asteroid families created during the simulation matches the number of observed families as well. We used new observational data from the WISE satellite (Masiero et al., 2011) to construct the observed SFDs. We simulate mutual collisions of asteroids with a modified version of the Boulder code (Morbidelli et al., 2009), where the results of hydrodynamic (SPH) simulations of Durda et al. (2007) and Benavidez et al. (2012) are included. Because material characteristics can significantly affect breakups, we created two models - for monolithic asteroids and for rubble-piles. To explain the observed SFDs in the size range D = 1 to 10 km we have to also account for dynamical depletion due to the Yarkovsky effect. The assumption of (purely) rubble-pile asteroids leads to a significantly worse fit to the observed data, so that we can conclude that majority of main-belt asteroids are rather monolithic. Our work may also serve as a motivation for further SPH simulations of disruptions of smaller targets (with a parent body size of the order of 1 km).Comment: Accepted for publication in Icaru