Speaker
Description
Gravitational waves from binary black hole mergers encode astrophysical information in multiple spherical harmonic modes. While dominant and subdominant modes have been extensively studied, the (l=2, m=0) mode has only recently been incorporated into waveform models.
We present a phenomenological waveform model for the (2,0) mode, capturing its two components: the non-oscillatory displacement memory and the quasi-normal ringdown. Incorporating this mode refines waveform accuracy, especially in the merger and post-merger regimes. Additionally, the displacement memory effect, which is mainly contained in this mode, remains undetected and this waveform model can be used to study its detectability. The model is first developed for aligned-spin binaries and then extended to precession, expanding its applicability across a wider parameter space.
Our implementation builds upon the computationally efficient IMRPhenomTHM and IMRPhenomTPHM models, which are optimal for Bayesian parameter estimation. Through extensive studies, we quantify the biases introduced when this mode is omitted, demonstrating its crucial role in accurately recovering individual mass and spin components and constraining the distance-inclination degeneracy. We present results for the Advanced LIGO A# sensitivity and Einstein Telescope.
Targeting the modeling of generic waveforms, we also present preliminary results regarding the (2,0) mode in eccentric systems.
By incorporating this missing piece of the gravitational wave signal, our work not only enhances the precision of parameter estimation, but also takes a step forward the possible detection of the displacement memory.
