119 research outputs found
Matched Filtering of Numerical Relativity Templates of Spinning Binary Black Holes
Tremendous progress has been made towards the solution of the
binary-black-hole problem in numerical relativity. The waveforms produced by
numerical relativity will play a role in gravitational wave detection as either
test-beds for analytic template banks or as template banks themselves. As the
parameter space explored by numerical relativity expands, the importance of
quantifying the effect that each parameter has on first the detection of
gravitational waves and then the parameter estimation of their sources
increases. In light of this, we present a study of equal-mass, spinning
binary-black-hole evolutions through matched filtering techniques commonly used
in data analysis. We study how the match between two numerical waveforms varies
with numerical resolution, initial angular momentum of the black holes and the
inclination angle between the source and the detector. This study is limited by
the fact that the spinning black-hole-binaries are oriented axially and the
waveforms only contain approximately two and a half orbits before merger. We
find that for detection purposes, spinning black holes require the inclusion of
the higher harmonics in addition to the dominant mode, a condition that becomes
more important as the black-hole-spins increase. In addition, we conduct a
preliminary investigation of how well a template of fixed spin and inclination
angle can detect target templates of arbitrary spin and inclination for the
axial case considered here
Zoom-Whirl Orbits in Black Hole Binaries
Zoom-whirl behavior has the reputation of being a rare phenomenon. The
concern has been that gravitational radiation would drain angular momentum so
rapidly that generic orbits would circularize before zoom-whirl behavior could
play out, and only rare highly tuned orbits would retain their imprint. Using
full numerical relativity, we catch zoom-whirl behavior despite dissipation.
The larger the mass ratio, the longer the pair can spend in orbit before
merging and therefore the more zooms and whirls seen. Larger spins also enhance
zoom-whirliness. An important implication is that these eccentric orbits can
merge during a whirl phase, before enough angular momentum has been lost to
truly circularize the orbit. Waveforms will be modulated by the harmonics of
zoom-whirls, showing quiet phases during zooms and louder glitches during
whirls.Comment: Replaced with published versio
Probing the Binary Black Hole Merger Regime with Scalar Perturbations
We present results obtained by scattering a scalar field off the curved
background of a coalescing binary black hole system. A massless scalar field is
evolved on a set of fixed backgrounds, each provided by a spatial hypersurface
generated numerically during a binary black hole merger. We show that the
scalar field scattered from the merger region exhibits quasinormal ringing once
a common apparent horizon surrounds the two black holes. This occurs earlier
than the onset of the perturbative regime as measured by the start of the
quasinormal ringing in the gravitational waveforms. We also use the scalar
quasinormal frequencies to associate a mass and a spin with each hypersurface,
and observe the compatibility of this measure with the horizon mass and spin
computed from the dynamical horizon framework.Comment: 10 Pages and 6 figure
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