Black Hole Spectroscopy Tools for Waveform Modelling

Next-generation gravitational-wave detectors will have enough sensitivity to resolve multiple ringdown frequencies from binary black hole mergers. This requires high-fidelity waveform models to extract as much information as possible from these signals and perform tests of general relativity.

In this talk, I will introduce two public tools for extracting the quasinormal mode amplitudes of binary black hole systems: qnmfits, which uses linear least-squares fitting, and NRSurr3dq8_RD, a surrogate model that uses machine learning to predict these amplitudes as well as remnant parameters for areas of parameter space where we lack simulations. With these tools at hand, one can easily build analytical ringdown waveforms.