We investigate pathways for the formation of icy super-Earth mass planets orbiting at 125-250 AU around a 1 solar mass star. An extensive suite of coagulation calculations demonstrates that swarms of 1 cm to 10 m planetesimals can form super-Earth ma
ss planets on time scales of 1-3 Gyr. Collisional damping of 0.01-100 cm particles during oligarchic growth is a highlight of these simulations. In some situations, damping initiates a second runaway growth phase where 100-3000 km protoplanets grow to super-Earth sizes. Our results establish the initial conditions and physical processes required for in situ formation of super-Earth planets at large distances from the host star. For nearby dusty disks in HD 107146, HD 202628, and HD 207129, ongoing super-Earth formation at 80-150 AU could produce gaps and other structures in the debris. In the solar system, forming a putative planet X at a < 300 AU (a > 1000 AU) requires a modest (very massive) protosolar nebula.
Hypervelocity stars (HVS) traverse the Galaxy from the central black hole to the outer halo. We show that the Galactic potential within 200 pc acts as a high pass filter preventing low velocity HVS from reaching the halo. To trace the orbits of HVS t
hroughout the Galaxy, we construct two forms of the potential which reasonably represent the observations in the range 5--100,000 pc, a simple spherically symmetric model and a bulge-disk-halo model. We use the Hills mechanism (disruption of binaries by the tidal field of the central black hole) to inject HVS into the Galaxy and compute the observable spatial and velocity distributions of HVS with masses in the range 0.6--4 Msun. These distributions reflect the mass function in the Galactic Center, properties of binaries in the Galactic Center, and aspects of stellar evolution and the injection mechanism. For 0.6--4 Msun main sequence stars, the fraction of unbound HVS and the asymmetry of the velocity distribution for their bound counterparts increases with stellar mass. The density profiles for unbound HVS decline with distance from the Galactic Center approximately as r^{-2} (but are steeper for the most massive stars which evolve off the main sequence during their travel time from the Galactic Center); the density profiles for the bound ejecta decline with distance approximately as r^{-3}. In a survey with a limiting visual magnitude V of 23, the detectability of HVS (unbound or bound) increases with stellar mass.
