Large mass-ratio ($3<q\le 10$) inspiral-merger-ringdown model for eccentric binary black holes

We present $\mathtt{\text{EccHybIMR22}}$, a fully analytical $\mathbf{\text{Ecc}}$entric-$\mathbf{\text{Hyb}}$rid-$\mathbf{\text{I}}$nspiral-$\mathbf{\text{M}}$erger-$\mathbf{\text{R}}$ingdown model for the quadrupole ($\mathrm{\ell }$=$2$, $\mathrm{\mid }m\mathrm{\mid }$=$2$ or simply the $\mathbf{\text{22}}$) mode. The model is obtained by smoothly attaching an eccentric-inspiral to a quasi-circular-merger-ringdown prescription and is trained on eccentric numerical relativity (NR) simulations with mass ratios $q\le 10$. In particular, we focus on obtaining a model that is sensitive to large mass ratios ($q>3$). Leveraging the recent expansion of SXS catalog of NR simulations, we construct a set of 91 hybrids (obtained by combining waveforms from post-Newtonian (PN) theory with NR simulations) with a target low total mass limit ($M_{\mathrm{l}\mathrm{o}\mathrm{w}}$) of $20M_{\odot }$ at an averaged 22 mode frequency of 20Hz, inaccessible with existing NR simulations alone. Employing a little less than a third of these hybrids as targets, we construct $\mathtt{\text{EccHybIMR22}}$ and recover $65\mathrm{\%}$ of the hybrids from the remaining set with mismatches smaller than $\sim 3\mathrm{\%}$ for a total mass of $40M_{\odot }$ (chosen arbitrarily) and orbital eccentricity $e_{20\mathrm{H}\mathrm{z}}\lesssim 0.33$ ($e_{20\mathrm{H}\mathrm{z}}\lesssim 0.12$) for mass ratios $q\le 3$ ($q>3$). Furthermore, when tested against 175 SXS simulations, the model is able to recover nearly $80\mathrm{\%}$ of the simulations with similar mismatches for systems with $0\lesssim e_{20\mathrm{H}\mathrm{z}}^{\mathrm{N}\mathrm{R}}\lesssim 0.3$.