Visualizing the black hole postmerger gravitational wave emission profile and horizon geometry

The gravitational waves produced by binary black hole systems with an asymmetric mass ratio exhibit a characteristic double-chirp pattern when viewed from a highly inclined orientation. These chirp patterns are composed of mixed higher-order modes produced during the postmerger stage, resulting from regions of high curvature on the distorted black hole horizon. Herein we utilize a parameterization of the double-chirp pattern using the continuous wavelet transform to map its direction of maximal emission on the sky of the final black hole. It is demonstrated that both the intrinsic properties of the system (mass ratio, spin), and the modal composition of the waveform have distinct impacts on the direction of emission and morphology of the maximal double-chirp pattern. Additionally, the application of this technique towards mapping the geometry of the final black hole horizon is discussed.