A&A 472, 1003-1015 (2007)
DOI: 10.1051/0004-6361:20077950
The effect of type I migration on the formation of terrestrial planets in hot-Jupiter systems
M. J. Fogg and R. P. NelsonAstronomy Unit, Queen Mary, University of London, Mile End Road, London E1 4NS, UK
e-mail: [M.J.Fogg;R.P.Nelson]@qmul.ac.uk
(Received 25 May 2007 / Accepted 16 July 2007)
Abstract
Context.Our previous models of a giant planet migrating through an inner
protoplanet/planetesimal disk find that the giant shepherds a
portion of the material it encounters into interior orbits, whilst
scattering the rest into external orbits. Scattering tends to
dominate, leaving behind abundant material that can accrete into
terrestrial planets.
Aims.We add to the possible realism of our model by simulating type I
migration forces which cause an inward drift, and
strong eccentricity and inclination damping of protoplanetary bodies.
This extra dissipation might be expected to enhance shepherding at the expense
of scattering, possibly modifying our previous conclusions.
Methods.We employ an N-body code that is linked to a viscous gas disk
algorithm capable of simulating: gas accretion onto the central
star; gap formation in the vicinity of the giant planet; type II
migration of the giant planet; type I migration of protoplanets; and
the effect of gas drag on planetesimals. We use the code to re-run
three scenarios from a previous work where type I migration was not
included.
Results.The additional dissipation introduced by type I migration enhances
the inward shepherding of material but does not severely reduce
scattering. We find that >50% of the solids disk material still
survives the migration in scattered exterior orbits: most of it well
placed to complete terrestrial planet formation at <3 AU. The
shepherded portion of the disk accretes into hot-Earths,
which survive in interior orbits for the duration of our simulations.
Conclusions.Water-rich terrestrial planets can form in the habitable zones of
hot-Jupiter systems and hot-Earths and hot-Neptunes may also be
present. These systems should be targets of future planet search
missions.
Key words: planets and satellites: formation -- methods: N-body simulations -- astrobiology
© ESO 2007

BibSonomy
CiteUlike
Del.icio.us
Digg
Facebook
Mendeley
Twitter