Analyzing the Quality of Recovered Orbital Periods

The APO Galactic Evolution Experiment APOGEE-1 and APOGEE-2 surveys took high-resolution H-Band spectroscopy of 263,444 stars (as of Data Release 15) and produced stellar radial velocities with of order 100 m/s precision. The combined surveys cover a base line of over 6 years (~2000 days). Of these, 6,200 stars have over 12 epochs of APOGEE data. With these time series data it is possible to search for and characterize stars with stellar and sub-stellar mass companions. Keplerian orbits can be described by six orbital elements (not including systemic velocity). Of those orbital elements, the period has the strongest effect in chi-squared space. In this project, we used a mock RV catalog spanning a range of periods and companion masses and sample with cadences similar to those used in the APOGEE surveys. We then apply Monte Carlo rejection sampling using The Joker (Price-Whelan et al. 2017) to recover orbital periods. In some cases, multiple periods were recovered for a given target. Thus we developed methods to understand the likelihood that we can trust a given result, and those methods are presented here.