Radial distribution of planets

Predictions based on the core-accretion gas-capture planet-formation model

¹ Max-Planck-Institute for Astronomy, Königstuhl 17, 69117 Heidelberg, Germany e-mail: kornet@mpia.de; swolf@mpia.de
² Nicolaus Copernicus Astronomical Center, Bartycka 18, Warsaw 00-716, Poland

Received: 24 July 2005
Accepted: 2 January 2006

Abstract

We have investigated the problem of the distribution of both masses and orbital radii of planets resulting from the gas-accretion, gas-capture model. First we followed the evolution of gas and solids from the moment where all solids are in the form of small grains to the stage when most of them are in the form of planetesimals for a set of different initial masses and sizes of protoplanetary disks. Based on that we performed Monte-Carlo calculations describing the formation of giant places at different locations. We included the effects of type II migration and growth of the mass of the planet after the gap opened. We discuss how these effects influence the final distribution of giant planets. We show that when the giant planets are not able to migrate or grow in mass after the gap opens, their distribution is mainly determined by the properties of the gaseous disk. However, with those two effects included, reproducing the parameters of the gaseous disks from the distribution of planets becomes difficult. We also checked the roles of both the material of which the solids consist and the mass of the central star. The main result is that, in disks around less massive stars, giant planets at the given location tend to be less massive. At the same time, the giant planets with the given mass tend to form closer to the less massive stars.