Systematic KMTNet Planetary Anomaly Search. XI. Complete Sample of 2016 Sub-Prime Field Planets

Following Shin et al. (2023b), which is a part of the Systematic KMTNetPlanetary Anomaly Search series (i.e., a search for planets in the 2016 KMTNetprime fields), we conduct a systematic search of the 2016 KMTNet sub-primefields using a semi-machine-based algorithm to identify hidden anomalous eventsmissed by the conventional by-eye search. We find four new planets and sevenplanet candidates that were buried in the KMTNet archive. The new planets areOGLE-2016-BLG-1598Lb, OGLE-2016-BLG-1800Lb, MOA-2016-BLG-526Lb, andKMT-2016-BLG-2321Lb, which show typical properties of microlensing planets,i.e., giant planets orbit M dwarf host stars beyond their snow lines. For theplanet candidates, we find planet/binary or 2L1S/1L2S degeneracies, which arean obstacle to firmly claiming planet detections. By combining the results ofShin et al. (2023b) and this work, we find a total of nine hidden planets,which is about half the number of planets discovered by eye in 2016. With thiswork, we have met the goal of the systematic search series for 2016, which isto build a complete microlensing planet sample. We also show that oursystematic searches significantly contribute to completing the planet sample,especially for planet/host mass ratios smaller than 10^-3, which wereincomplete in previous by-eye searches of the KMTNet archive.