# Item

ITEM ACTIONSEXPORT

Released

Journal Article

#### Eccentric binary black hole surrogate models for the gravitational waveform and remnant properties: comparable mass, nonspinning case

##### External Resource

No external resources are shared

##### Fulltext (restricted access)

There are currently no full texts shared for your IP range.

##### Fulltext (public)

2101.11798.pdf

(Preprint), 2MB

##### Supplementary Material (public)

There is no public supplementary material available

##### Citation

Islam, T., Varma, V., Lodman, J., Field, S. E., Khanna, G., Scheel, M. A., et al. (2021).
Eccentric binary black hole surrogate models for the gravitational waveform and remnant properties: comparable mass, nonspinning
case.* Physical Review D,* *103*(6): 064022. doi:10.1103/PhysRevD.103.064022.

Cite as: https://hdl.handle.net/21.11116/0000-0008-33D0-3

##### Abstract

We develop new strategies to build numerical relativity surrogate models for

eccentric binary black hole systems, which are expected to play an increasingly

important role in current and future gravitational-wave detectors. We introduce

a new surrogate waveform model, \texttt{NRSur2dq1Ecc}, using 47 nonspinning,

equal-mass waveforms with eccentricities up to $0.2$ when measured at a

reference time of $5500M$ before merger. This is the first waveform model that

is directly trained on eccentric numerical relativity simulations and does not

require that the binary circularizes before merger. The model includes the

$(2,2)$, $(3,2)$, and $(4,4)$ spin-weighted spherical harmonic modes. We also

build a final black hole model, \texttt{NRSur2dq1EccRemnant}, which models the

mass, and spin of the remnant black hole. We show that our waveform model can

accurately predict numerical relativity waveforms with mismatches $\approx

10^{-3}$, while the remnant model can recover the final mass and dimensionless

spin with errors smaller than $\approx 5 \times 10^{-4}M$ and $\approx 2

\times10^{-3}$ respectively. We demonstrate that the waveform model can also

recover subtle effects like mode-mixing in the ringdown signal without any

special ad-hoc modeling steps. Finally, we show that despite being trained only

on equal-mass binaries, \texttt{NRSur2dq1Ecc} can be reasonably extended up to

mass ratio $q\approx3$ with mismatches $\simeq 10^{-2}$ for eccentricities

smaller than $\sim 0.05$ as measured at a reference time of $2000M$ before

merger. The methods developed here should prove useful in the building of

future eccentric surrogate models over larger regions of the parameter space.

eccentric binary black hole systems, which are expected to play an increasingly

important role in current and future gravitational-wave detectors. We introduce

a new surrogate waveform model, \texttt{NRSur2dq1Ecc}, using 47 nonspinning,

equal-mass waveforms with eccentricities up to $0.2$ when measured at a

reference time of $5500M$ before merger. This is the first waveform model that

is directly trained on eccentric numerical relativity simulations and does not

require that the binary circularizes before merger. The model includes the

$(2,2)$, $(3,2)$, and $(4,4)$ spin-weighted spherical harmonic modes. We also

build a final black hole model, \texttt{NRSur2dq1EccRemnant}, which models the

mass, and spin of the remnant black hole. We show that our waveform model can

accurately predict numerical relativity waveforms with mismatches $\approx

10^{-3}$, while the remnant model can recover the final mass and dimensionless

spin with errors smaller than $\approx 5 \times 10^{-4}M$ and $\approx 2

\times10^{-3}$ respectively. We demonstrate that the waveform model can also

recover subtle effects like mode-mixing in the ringdown signal without any

special ad-hoc modeling steps. Finally, we show that despite being trained only

on equal-mass binaries, \texttt{NRSur2dq1Ecc} can be reasonably extended up to

mass ratio $q\approx3$ with mismatches $\simeq 10^{-2}$ for eccentricities

smaller than $\sim 0.05$ as measured at a reference time of $2000M$ before

merger. The methods developed here should prove useful in the building of

future eccentric surrogate models over larger regions of the parameter space.