Oral Presentation

Nanohertz gravitational waves and SMBH binaries

Author(s): Kin-Wang Ng (ASIOP/ASIAA)

Presenter: Kin-Wang Ng (ASIOP/ASIAA)

Pulsar timing arrays (PTAs) have reported a compelling evidence of a nanohertz stochastic gravitational wave background. However, the origin of the signal remains undetermined, largely because its spectrum is bluer for an astrophysical source and can be explained by cosmological models. We show that a common power law traditionally used to interpret a stochastic gravitational wave background signal is generally faced with systematic errors, one of which is the illusion of a bluer signal. This hints at a conservative solution, supportive of an astrophysical source, to the observed correlated common spectrum process in PTAs. We also mention a possible PTA detection of a single SMBH binary event.