449 research outputs found
Surrogate model for gravitational wave signals from comparable and large-mass-ratio black hole binaries
Gravitational wave signals from compact astrophysical sources such as those observed by LIGO and Virgo require a high-accuracy, theory-based waveform model for the analysis of the recorded signal. Current inspiral-merger-ringdown models are calibrated only up to moderate mass ratios, thereby limiting their applicability to signals from high-mass-ratio binary systems. We present EMRISur1dq1e4, a reduced-order surrogate model for gravitational waveforms of
13
500
M
in duration and including several harmonic modes for nonspinning black hole binary systems with mass ratios varying from 3 to 10000, thus vastly expanding the parameter range beyond the current models. This surrogate model is trained on waveform data generated by point-particle black hole perturbation theory (ppBHPT) both for large-mass-ratio and comparable mass-ratio binaries. We observe that the gravitational waveforms generated through a simple application of ppBHPT to the comparable mass-ratio cases agree surprisingly well with those from full numerical relativity after a rescaling of the ppBHPT’s total mass parameter. This observation and the EMRISur1dq1e4 surrogate model will enable data analysis studies in the high-mass-ratio regime, including potential intermediate-mass-ratio signals from LIGO/Virgo and extreme-mass-ratio events of interest to the future space-based observatory LISA
Surrogate models for precessing binary black hole simulations with unequal masses
Only numerical relativity simulations can capture the full complexities of
binary black hole mergers. These simulations, however, are prohibitively
expensive for direct data analysis applications such as parameter estimation.
We present two new fast and accurate surrogate models for the outputs of these
simulations: the first model, NRSur7dq4, predicts the gravitational waveform
and the second model, \RemnantModel, predicts the properties of the remnant
black hole. These models extend previous 7-dimensional, non-eccentric
precessing models to higher mass ratios, and have been trained against 1528
simulations with mass ratios and spin magnitudes , with generic spin directions. The waveform model, NRSur7dq4, which begins
about 20 orbits before merger, includes all spin-weighted
spherical harmonic modes, as well as the precession frame dynamics and spin
evolution of the black holes. The final black hole model, \RemnantModel, models
the mass, spin, and recoil kick velocity of the remnant black hole. In their
training parameter range, both models are shown to be more accurate than
existing models by at least an order of magnitude, with errors comparable to
the estimated errors in the numerical relativity simulations. We also show that
the surrogate models work well even when extrapolated outside their training
parameter space range, up to mass ratios .Comment: Matches published version. Models publicly available at
https://zenodo.org/record/3455886#.XZ9s1-dKjBI and
https://pypi.org/project/surfinB
Extracting the Gravitational Recoil from Black Hole Merger Signals
Gravitational waves carry energy, angular momentum, and linear momentum. In generic binary black hole mergers, the loss of linear momentum imparts a recoil velocity, or a “kick,” to the remnant black hole. We exploit recent advances in gravitational waveform and remnant black hole modeling to extract information about the kick from the gravitational wave signal. Kick measurements such as these are astrophysically valuable, enabling independent constraints on the rate of second-generation merger. Further, we show that kicks must be factored into future ringdown tests of general relativity with third-generation gravitational wave detectors to avoid systematic biases. We find that, although little information can be gained about the kick for existing gravitational wave events, interesting measurements will soon become possible as detectors improve. We show that, once LIGO and Virgo reach their design sensitivities, we will reliably extract the kick velocity for generically precessing binaries—including the so-called superkicks, reaching up to 5000 km/s
Surrogate model for gravitational wave signals from non-spinning, comparable- to large-mass-ratio black hole binaries built on black hole perturbation theory waveforms calibrated to numerical relativity
We present a reduced-order surrogate model of gravitational waveforms from
non-spinning binary black hole systems with comparable to large mass-ratio
configurations. This surrogate model, \texttt{BHPTNRSur1dq1e4}, is trained on
waveform data generated by point-particle black hole perturbation theory
(ppBHPT) with mass ratios varying from 2.5 to 10,000. \texttt{BHPTNRSur1dq1e4}
extends an earlier waveform model, \texttt{EMRISur1dq1e4}, by using an updated
transition-to-plunge model, covering longer durations up to 30,500 (where
is the mass of the primary black hole), includes several more spherical
harmonic modes up to , and calibrates subdominant modes to numerical
relativity (NR) data. In the comparable mass-ratio regime, including mass
ratios as low as , the gravitational waveforms generated through ppBHPT
agree surprisingly well with those from NR after this simple calibration step.
We also compare our model to recent SXS and RIT NR simulations at mass ratios
ranging from to , and find the dominant quadrupolar modes agree to
better than . We expect our model to be useful to study
intermediate-mass-ratio binary systems in current and future gravitational-wave
detectors.Comment: 20 pages, 15 figure
Survey of gravitational wave memory in intermediate mass ratio binaries
The non-linear gravitational wave (GW) memory effect is a distinct prediction
in general relativity. While the effect has been well studied for comparable
mass binaries, it has mostly been overlooked for intermediate mass ratio
inspirals (IMRIs). We offer a comprehensive analysis of the phenomenology and
detectability of memory effects, including contributions from subdominant
harmonic modes, in heavy IMRIs consisting of a stellar mass black hole and an
intermediate mass black hole. When formed through hierarchical mergers, for
example when a GW190521-like remnant captures a stellar mass black hole, IMRI
systems have a large total mass, large spin on the primary, and possibly
residual eccentricity; features that potentially raise the prospect for memory
detection. We compute both the displacement and spin non-linear GW memory from
the gravitational waveforms computed within a black hole
perturbation theory framework that is partially calibrated to numerical
relativity waveforms. We probe the dependence of memory effects on mass ratio,
spin, and eccentricity and consider the detectability of a memory signal from
IMRIs using current and future GW detectors. We find that (i) while
eccentricity introduces additional features in both displacement and spin
memory, it does not appreciatively change the prospects of detectability, (ii)
including higher modes into the memory computation can increase singal-to-noise
(SNR) values by about 7\% in some cases, (iii) the SNR from displacement memory
dramatically increases as the spin approaches large, positive values, (iv) spin
memory from heavy IMRIs would, however, be difficult to detect with future
generation detectors even from highly spinning systems. Our results suggest
that hierarchical binary black hole mergers may be a promising source for
detecting memory and could favorably impact memory forecasts.Comment: 18 pages, 17 figures, matches the version published in PR
The SXS Collaboration catalog of binary black hole simulations
Accurate models of gravitational waves from merging black holes are necessary
for detectors to observe as many events as possible while extracting the
maximum science. Near the time of merger, the gravitational waves from merging
black holes can be computed only using numerical relativity. In this paper, we
present a major update of the Simulating eXtreme Spacetimes (SXS) Collaboration
catalog of numerical simulations for merging black holes. The catalog contains
2018 distinct configurations (a factor of 11 increase compared to the 2013 SXS
catalog), including 1426 spin-precessing configurations, with mass ratios
between 1 and 10, and spin magnitudes up to 0.998. The median length of a
waveform in the catalog is 39 cycles of the dominant
gravitational-wave mode, with the shortest waveform containing 7.0 cycles and
the longest 351.3 cycles. We discuss improvements such as correcting for moving
centers of mass and extended coverage of the parameter space. We also present a
thorough analysis of numerical errors, finding typical truncation errors
corresponding to a waveform mismatch of . The simulations provide
remnant masses and spins with uncertainties of 0.03% and 0.1% (
percentile), about an order of magnitude better than analytical models for
remnant properties. The full catalog is publicly available at
https://www.black-holes.org/waveforms .Comment: 33+18 pages, 13 figures, 4 tables, 2,018 binaries. Catalog metadata
in ancillary JSON file. v2: Matches version accepted by CQG. Catalog
available at https://www.black-holes.org/waveform
Interplay between numerical relativity and perturbation theory : finite size effects
We investigate the interplay between numerical relativity (NR) and
point-particle black hole perturbation theory (ppBHPT) in the comparable mass
ratio regime. In the ppBHPT framework, the secondary black hole is treated as a
point particle, neglecting its finite size. Our study focuses on addressing the
missing finite size effect in the ppBHPT framework and proposing a method for
incorporating the size of the secondary into the perturbation theory framework.
We demonstrate that by considering the secondary as a finite size object, the
BHPT waveforms closely match NR waveforms. Additionally, we revisit the
- scaling technique, which was previously introduced by Islam et
al, as a means to effectively match ppBHPT waveforms to NR waveforms. We
further analyze the scaling procedure and decompose it into different
components, attributing them to various effects, including the corrections
arising from the finite size of the secondary black hole.Comment: 12 pages, 10 figure
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