  It has been shown that some aspects of the terrestrial planets can be
explained, particularly the Earth/Mars mass ratio, when they form from a
truncated disk with an outer edge near 1.0 au (Hansen 2009). This has been
previously modeled starting from an intermediate stage of growth utilizing
pre-formed planetary embryos. We present simulations that were designed to test
this idea by following the growth process from km-sized objects located between
0.7 to 1.0 au up to terrestrial planets. The simulations explore initial
conditions where the solids in the disk are planetesimals with radii initially
between 3 and 300 km, alternately including effects from a dissipating gaseous
solar nebula and collisional fragmentation. We use a new Lagrangian code known
as LIPAD (Levison et al. 2012), which is a particle-based code that models the
fragmentation, accretion and dynamical evolution of a large number of
planetesimals, and can model the entire growth process from km-sizes up to
planets. A suite of large (Mars mass) planetary embryos is complete in only 1
Myr, containing most of the system mass. A quiescent period then persists for
10-20 Myr characterized by slow diffusion of the orbits and continued accretion
of the remaining planetesimals. This is interupted by an instability that leads
to embryos crossing orbits and embyro-embryo impacts that eventually produce
the final set of planets. While this evolution is different than that found in
other works exploring an annulus, the final planetary systems are similar, with
roughly the correct number of planets and good Mars-analogs.
