演講資訊

摘要：

In this work we explore the long-term dynamical evolution of a bias-free orbital representation of the Kuiper belt, the so-called L7 synthetic model from CFEPS, under the gravitational influence of the Sun and the four giant planets, as well as of the 34 largest known TNOs, those with visual absolute magnitude H_V < 4, among which are the four objects currently classified as dwarf planets by the IAU (Pluto, Eris, Haumea, and Makemake); however, in this work we indistinctively call Dwarf Planets (DPs) to all the objects in our 34 members set. Over 1 Gyr time-scales, we analyzed the secular influence of the DPs over Kuiper belt particles and their contribution to the injection rate of new visible Jupiter Family Comets (JFCs), as they make their way from the Scattering, Resonant, and Classical populations to the inner Solar System. We found that DPs effectively increase the number of new visible JFCs originating from the Classical and Resonant populations in almost 20%, when compared with the number of comets produced by the giant planets alone. For the Scattering population the increment is marginal but noticeable. Given the rate of escapes from the Kuiper belt enhanced by DPs, 20% less objects in the Classical and Resonant populations are required to supply the number of JFCs currently observed. Considering recent estimates of the injection rate of  new comets  required to maintain the population  of JFCs in steady state, the maximum numbers of 1 to 10 km sized objects required to supply the 100% of new JFCs are: ∼5.9×10^7, ∼1.0×10^8, and ∼2.9×10^8 for the Scattering, Resonant, and Classical populations, respectively. By comparing with the  number of objects in the same size range expected to be present on each of these populations from recent cratering records predictions on the surface of 2014 MU69, we provide some estimates of the fractional contribution of each population to new visible JFCs. Additionally, we found that the Plutinos are the most important source of comets originally coming from a resonant configuration, where the presence of Pluto and the large plutinos Orcus, 2003 AZ84, and Ixion, are important to increase the number of unstable 3:2 resonators. On the other hand, the twotinos and the populations in the 5:3 and 5:2 mean motion resonances with Neptune all supply a comparable amount of new visible JFCs.