Orateur
Description
Unveiling the nature of the nanoHz gravitational wave signal reported by Pulsar Timing Array collaborations is the next goal of low-frequency GW astronomy. The signal likely originates from the incoherent superposition of GWs emitted by a population of supermassive black hole binaries (SMBHBs). The discrete nature of the population, environmental effects and eccentricity are expected to produce significant deviations of the GWB power spectrum from the smooth powerlaw approximation.
In this talk I explore the possibility of modeling the GWB using a t-process power spectral density. This model also takes into account possible extra power in specific frequency bins, which may arise from single sources dominating the GWB. I will present results from testing the model on real PTA datasets and on simulations of realistic populations to evaluate the ability to detect a more complex PSD that deviates from the powerlaw. I will discuss current limitations and potential improvements of the model.