Abstract

The aftermath of binary black hole coalescence is a perturbed remnant whose gravitational radiation rings down, encoding information about the new black hole’s recent history and current state. It is expected that this ringdown radiation will be composed primarily of Kerr quasi-normal modes, and thereby enable tests of general relativity. In this talk I present the first ringdown model that captures the amplitude and relative phase of the dominant and subdominant quasi-normal modes for non-precessing binary black holes systems. For the first time it is noticed that the dominant mode’s excitation is a remarkably simple function of system parameters, suggesting that an analytic treatment may be within reach. Application of the model to parameter estimation indicates that some mode amplitudes and relative phases are in general very difficult to constrain, while others are well constrained, even for low SNR signals. GW150914 is discussed as an example case.