Targeted large mass ratio numerical relativity surrogate waveform model for GW190814
J. Yoo, Vijay Varma, Matthew Giesler, Mark Scheel, C.‐J. Haster, Harald Pfeiffer, Lawrence E. Kidder, Michael Boyle
Abstract
Gravitational wave observations of large mass ratio compact binary mergers like GW190814 highlight the need for reliable, high-accuracy waveform templates for such systems. We present nrhybsur2dq15, a new surrogate model trained on hybridized numerical relativity (NR) waveforms with mass ratios $q\ensuremath{\le}15$ and aligned spins $|{\ensuremath{\chi}}_{1z}|\ensuremath{\le}0.5$ and ${\ensuremath{\chi}}_{2z}=0$. We target the parameter space of GW190814-like events as large mass ratio NR simulations are very expensive. The model includes the (2, 2), (2, 1), (3, 3), (4, 4), and (5, 5) spin-weighted spherical harmonic modes and spans the entire LIGO-Virgo bandwidth (with ${f}_{\mathrm{low}}=20\text{ }\text{ }\mathrm{Hz}$) for total masses $M\ensuremath{\gtrsim}9.5\text{ }\text{ }{M}_{\ensuremath{\bigodot}}$. nrhybsur2dq15 accurately reproduces the hybrid waveforms, with mismatches below $\ensuremath{\sim}2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$ for total masses $10\text{ }\text{ }{M}_{\ensuremath{\bigodot}}\ensuremath{\le}M\ensuremath{\le}300\text{ }\text{ }{M}_{\ensuremath{\bigodot}}$. This is at least an order of magnitude improvement over existing semianalytical models for GW190814-like systems. Finally, we reanalyze GW190814 with the new model and obtain source parameter constraints consistent with previous work.