The origin and distribution of the Centaur population

Abstract

We analyze the Centaur population as a group of objects with perihelion distances ( q) of less than 30 AU and heliocentric distances outside the orbit of Jupiter, formed by objects entering this region from the Scattered Disk (SD). We perform a numerical integration of 95 real Scattered Disk Objects (SDOs) extracted from the Minor Planet Center database and of 905 synthetic SDOs compensating for observational biases. SDOs have in the Centaur zone a mean lifetime of 72 Myr, though this number falls with a decrease of q. After this incursion, 30% of them enter the zone interior to Jupiter's orbit. We find that the contribution to the Centaur population from the SD gives a total of ∼ 2.8 × 10 8 Centaurs with a radius R > 1 km . We also propose a model for the intrinsic distribution of orbital elements of Centaurs and their distance and apparent magnitude distribution.