We carried out simulations to predict the distributions of masses and
semi major axes (periods) of extra solar planets, modelling the
accretion of cores of giant planets from planetesimals,
gas accretion onto the cores, and their orbital migration. We adopted
a working model for nascent protostellar disks with a wide variety of
surface density distributions, which are comparable to those inferred
from the observations of circumstellar disks of T Tauri stars.
Since planets' masses grow rapidly from 10 M_E to 100 M_E, we predict
that the gas giant planets rarely form with asymptotic masses in
this intermediate mass range at < 3AU. We refer to this deficit as
a ``planet desert''. We also predict that the frequency of gas giant
planets that are detectable with current radial velocity search is
greatly enhanced in metal-rich protostellar disks, which is consistent
with the observation. Protoplanetary cores can grow to several
Earth masses prior to the disk gas depletion in such environment and
these large masses are required for the cores to initiate rapid gas
accretion and to transform into giant planets.
We also suggest that more than ninety percent of planets migrated to the
vicinity of their host stars are perished.
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