The North American Nanohertz Observatory for Gravitational Waves (NANOGrav) times periodic signals from pulsars as a method of detecting gravitational waves. NANOGrav detects waves emitted in the nanohertz frequency range, a range lower than those previously explored by other organizations. This allows for the study of rarely observed sources such as supermassive black hole binary systems. To increase the accuracy of their detections, NANOGrav regularly searches for pulsars to add to their timing array. This involves determining which of thousands of periodic signals observed by radio telescopes have the distinguishing characteristics of pulsars. This paper covers the methods of distinction of pulsar signals from other radio signals based on several characteristics including the signal’s pulse profile, dispersion measure, frequency, and significance. 1,432 candidates are classified based on their likelihood of being a signal from a pulsar, and several candidates are discussed directly. Candidates determined to be likely pulsars may be followed up for timing by NANOGrav. Candidates of all classifications may be used to train future researchers and artificial intelligence systems on the ranking process. Each new pulsar discovered will improve the accuracy of NANOGrav’s dataset, increasing our sensitivity to gravitational waves and furthering our understanding of their sources.

Jaden Downing is a senior in Physics. She is a member of NANOGrav and her research is supervised by Prof. Xavier Siemens.