  As accretion in protoplanetary disks is enabled by turbulent viscosity, the
border between active and inactive (dead) zones constitutes a location where
there is an abrupt change in the accretion flow. The gas accumulation that
ensues triggers the Rossby wave instability, that in turn saturates into
anticyclonic vortices. It was suggested that the trapping of solids within them
leads to a burst of planet formation on very short timescales. We perform
two-dimensional global simulations of the dynamics of gas and solids in a
non-magnetized thin protoplanetary disk with the Pencil Code. We use multiple
particle species of radius 1, 10, 30, and 100 cm, solving for the particles'
gravitational interaction by a particle-mesh method. The dead zone is modeled
as a region of low viscosity. Adiabatic and locally isothermal equations of
state are used. We find that the Rossby wave instability is triggered under a
variety of conditions, thus making vortex formation a robust process. Inside
the vortices, fast accumulation of solids occurs and the particles collapse
into objects of planetary mass in timescales as short as five orbits. Because
the drag force is size-dependent, aerodynamical sorting ensues within the
vortical motion, and the first bound structures formed are composed primarily
of similarly-sized particles. In addition to erosion due to ram pressure, we
identify gas tides from the massive vortices as a disrupting agent of formed
protoplanetary embryos. We also estimate the collisional velocity history of
the particles that compose the most massive embryo by the end of the
simulation, finding that the vast majority of them never experienced a
collision with another particle at speeds faster than 1 m/s.
