Planet Frequency beyond the Snow Line from MOA-II Microlensing Survey

We present the first statistical analysis of the exoplanet frequency using planets found by a microlensing survey rather than follow-up observations. We present an analysis of 2007-2012 MOA (Microlensing Observations in Astrophysics) survey data to derive the planet frequency as a function of the planet/star mass ratio, q and separation, s, relative to the Einstein radius. Our sample includes 1472 microlensing events, including 22 planetary events and 1 ambiguous event with possible planetary and stellar binary solutions. The detection efficiency is calculated for each event and we employ a Bayesian analysis to deal with the ambiguous event. A broken power law model is used to fit the mass ratio function and we find a break and likely peak at q ~1.0^-4.