Speaker
Description
We investigate the prospects for detecting nanohertz gravitational waves from individual supermassive black hole binaries (SMBHBs) using pulsar timing arrays (PTAs). We review the formation and gravitational radiation of SMBHBs, the principles of pulsar timing, and the current observational capabilities of PTAs, with particular emphasis on the expected sensitivity improvements offered by the Square Kilometre Array (SKA). Using electromagnetic observations to estimate the gravitational-wave parameters of four SMBHB candidates—OJ 287, 3C 66B, NGC 5548, and S5 1928+738—we calculate their expected strain amplitudes and signal-to-noise ratios for several future PTA configurations. Our sensitivity forecasts indicate that, under idealized white-noise assumptions and the adopted binary models, gravitational waves from OJ 287, 3C 66B, and NGC 5548 could exceed the nominal detection threshold of the SKA. S5 1928+738 may also become detectable with sufficiently sensitive configurations. Furthermore, comparison with a larger population of electromagnetically identified SMBHB candidates suggests that numerous additional sources could approach or exceed the SKA detection threshold. These results highlight the potential of the SKA to detect continuous gravitational waves from multiple individual SMBHBs, opening new opportunities for multimessenger astronomy and for understanding the formation and evolution of supermassive black holes.