4 research outputs found
Testing the Kerr nature of intermediate-mass and supermassive black hole binaries using spin-induced multipole moment measurements
The gravitational wave measurements of spin-induced multipole moment
coefficients of a binary black hole system can be used to distinguish black
holes from other compact objects [N. V. Krishnendu et al., PRL 119, 091101
(2017)]. Here, we apply the idea proposed in [N. V. Krishnendu et al., PRL 119,
091101 (2017)] to binary systems composed of intermediate-mass and supermassive
black holes and derive the expected bounds on their Kerr nature using future
space-based gravitational wave detectors. Using astrophysical models of binary
black hole population, we study the measurability of the spin-induced
quadrupole and octupole moment coefficients using LISA and DECIGO. The errors
on spin-induced quadrupole moment parameter of the binary system are found to
be { for almost of the total supermassive binary black hole
population which is detectable by LISA whereas it is for the
intermediate-mass black hole binaries observable by DECIGO at its design
sensitivity.} We find that { errors on} {\it both} the quadrupole and octupole
moment parameters can be estimated to { be} for and {of the population} respectively for LISA and DECIGO detectors. { Our
findings suggest that a subpopulation of binary black hole events, with the
signal to noise ratio thresholds greater than 200 and 100 respectively for LISA
and DECIGO detectors, would permit tests of black hole nature to 10\%
precision.}Comment: 7 pages, 6 figure
Surrogate light curve models for kilonovae with comprehensive wind ejecta outflows and parameter estimation for AT2017gfo
The electromagnetic emission resulting from neutron star mergers have been
shown to encode properties of the ejected material in their light curves. The
ejecta properties inferred from the kilonova emission has been in tension with
those calculated based on the gravitational wave signal and numerical
relativity models. Motivated by this tension, we construct a broad set of
surrogate light curve models derived for kilonova ejecta. The four-parameter
family of two-dimensional anisotropic simulations and its associated surrogate
explore different assumptions about the wind outflow morphology and outflow
composition, keeping the dynamical ejecta component consistent. We present the
capabilities of these surrogate models in interpolating kilonova light curves
across various ejecta parameters and perform parameter estimation for AT2017gfo
both without any assumptions on the outflow and under the assumption that the
outflow must be representative of solar r-process abundance patterns. Our
parameter estimation for AT2017gfo shows these surrogate models help alleviate
the ejecta property discrepancy while also illustrating the impact of
systematic modeling uncertainties on these properties, urging further
investigation.Comment: 15 pages, 6 figures, data available in Zenodo
(https://zenodo.org/record/7335961) and GitHub
(https://github.com/markoris/surrogate_kne
Search for intermediate-mass black hole binaries in the third observing run of Advanced LIGO and Advanced Virgo
International audienceIntermediate-mass black holes (IMBHs) span the approximate mass range 100â105âMâ, between black holes (BHs) that formed by stellar collapse and the supermassive BHs at the centers of galaxies. Mergers of IMBH binaries are the most energetic gravitational-wave sources accessible by the terrestrial detector network. Searches of the first two observing runs of Advanced LIGO and Advanced Virgo did not yield any significant IMBH binary signals. In the third observing run (O3), the increased network sensitivity enabled the detection of GW190521, a signal consistent with a binary merger of mass âŒ150âMâ providing direct evidence of IMBH formation. Here, we report on a dedicated search of O3 data for further IMBH binary mergers, combining both modeled (matched filter) and model-independent search methods. We find some marginal candidates, but none are sufficiently significant to indicate detection of further IMBH mergers. We quantify the sensitivity of the individual search methods and of the combined search using a suite of IMBH binary signals obtained via numerical relativity, including the effects of spins misaligned with the binary orbital axis, and present the resulting upper limits on astrophysical merger rates. Our most stringent limit is for equal mass and aligned spin BH binary of total mass 200âMâ and effective aligned spin 0.8 at 0.056 Gpcâ3 yrâ1 (90% confidence), a factor of 3.5 more constraining than previous LIGO-Virgo limits. We also update the estimated rate of mergers similar to GW190521 to 0.08 Gpcâ3 yrâ1.Key words: gravitational waves / stars: black holes / black hole physicsCorresponding author: W. Del Pozzo, e-mail: [email protected]â Deceased, August 2020