Evidence of outer planet migration in the orbital distribution of the Kuiper belt objects
The Kuiper belt consists of two main groups which are usually called the 'hot' and 'cold' populations. Very different orbital and physical properties of these populations imply a different dynamical origin. While the 'hot' population could be delivered to the Kuiper belt from the region interior to ~35 AU during the high-eccentricity phase of Neptune's migration (Levison et al., 2008, Icarus, 196, 258), the explanation of the origin for the 'cold' population needs considering processes with much smaller dynamical excitation. We investigate dynamical features of migration of low mass planets into the Kuiper belt region. Various profiles for the surface density of a planetesimal disk and masses of migrating planets are studied. It is shown that an Earth-mass planet, typically, reverses its migration near an outer edge of the planetesimal disc. Many objects move from the inner planetesimal disc to the Kuiper belt region during the planetary migration. After transferring objects to the Kuiper belt the planet returns to the inner region. The migration of the Earth-mass planet in the trans-Neptunian planetesimal disk reproduces well general orbital characteristics of the 'cold' Kuiper belt population.