A Multimessenger Search for the Supermassive Black Hole Binary in 3C 66B with the Parkes Pulsar Timing Array

Abstract

A subparsec supermassive black hole binary (SMBHB) at the center of the galaxy 3C 66B is a promising candidate for continuous gravitational-wave searches with pulsar timing arrays (PTAs). In this work, we search for such a signal in the third data release of the Parkes Pulsar Timing Array. Matching our priors to estimates of binary parameters from electromagnetic (EM) observations, we find a log Bayes factor ln B = − 0.0027 (7), highlighting that the source can be neither confirmed nor ruled out. We place upper limits at 95% credibility on the chirp mass M < 6.90 × 1 0 8 M ⊙, and on the characteristic strain amplitude log 10 (h 0) < − 14.44. This partially rules out the parameter space sugge..