4,453 research outputs found
Deep Learning for Real-time Gravitational Wave Detection and Parameter Estimation: Results with Advanced LIGO Data
The recent Nobel-prize-winning detections of gravitational waves from merging
black holes and the subsequent detection of the collision of two neutron stars
in coincidence with electromagnetic observations have inaugurated a new era of
multimessenger astrophysics. To enhance the scope of this emergent field of
science, we pioneered the use of deep learning with convolutional neural
networks, that take time-series inputs, for rapid detection and
characterization of gravitational wave signals. This approach, Deep Filtering,
was initially demonstrated using simulated LIGO noise. In this article, we
present the extension of Deep Filtering using real data from LIGO, for both
detection and parameter estimation of gravitational waves from binary black
hole mergers using continuous data streams from multiple LIGO detectors. We
demonstrate for the first time that machine learning can detect and estimate
the true parameters of real events observed by LIGO. Our results show that Deep
Filtering achieves similar sensitivities and lower errors compared to
matched-filtering while being far more computationally efficient and more
resilient to glitches, allowing real-time processing of weak time-series
signals in non-stationary non-Gaussian noise with minimal resources, and also
enables the detection of new classes of gravitational wave sources that may go
unnoticed with existing detection algorithms. This unified framework for data
analysis is ideally suited to enable coincident detection campaigns of
gravitational waves and their multimessenger counterparts in real-time.Comment: 6 pages, 7 figures; First application of deep learning to real LIGO
events; Includes direct comparison against matched-filterin
Importance of including small body spin effects in the modelling of intermediate mass-ratio inspirals. II Accurate parameter extraction of strong sources using higher-order spin effects
We improve the numerical kludge waveform model introduced in [1] in two ways.
We extend the equations of motion for spinning black hole binaries derived by
Saijo et al. [2] using spin-orbit and spin-spin couplings taken from
perturbative and post-Newtonian (PN) calculations at the highest order
available. We also include first-order conservative self-force corrections for
spin-orbit and spin-spin couplings, which are derived by comparison to PN
results. We generate the inspiral evolution using fluxes that include the most
recent calculations of small body spin corrections, spin-spin and spin-orbit
couplings and higher-order fits to solutions of the Teukolsky equation. Using a
simplified version of this model in [1], we found that small body spin effects
could be measured through gravitational wave observations from
intermediate-mass ratio inspirals (IMRIs) with mass ratio eta ~ 0.001, when
both binary components are rapidly rotating. In this paper we study in detail
how the spin of the small/big body affects parameter measurement using a
variety of mass and spin combinations for typical IMRIs sources. We find that
for IMRI events of a moderately rotating intermediate mass black hole (IMBH) of
ten thousand solar masses, and a rapidly rotating central supermassive black
hole (SMBH) of one million solar masses, gravitational wave observations made
with LISA at a fixed signal-to-noise ratio (SNR) of 1000 will be able to
determine the inspiralling IMBH mass, the central SMBH mass, the SMBH spin
magnitude, and the IMBH spin magnitude to within fractional errors of ~0.001,
0.001, 0.0001, and 9%, respectively. LISA can also determine the location of
the source in the sky and the SMBH spin orientation to within ~0.0001
steradians. We show that by including conservative corrections up to 2.5PN
order, systematic errors no longer dominate over statistical errors for IMRIs
with typical SNR ~1000.Comment: 21 pages, 7 figures. v2: three references added, edits in Sections
II-V, including additional results in Section V to address comments by the
referee. v3: mirrors version accepted to PR
Importance of including small body spin effects in the modelling of extreme and intermediate mass-ratio inspirals
We explore the ability of future low-frequency gravitational wave detectors
to measure the spin of stellar mass and intermediate mass black holes that
inspiral onto super-massive Kerr black holes (SMBHs). We develop a kludge
waveform model based on the equations of motion derived by Saijo et al. [Phys
Rev D 58, 064005, 1998] for spinning BH binaries, augmented with spin-orbit and
spin-spin couplings taken from perturbative and post-Newtonian (PN)
calculations, and the associated conservative self-force corrections, derived
by comparison to PN results. We model the inspiral phase using accurate fluxes
which include perturbative corrections for the spin of the inspiralling body,
spin-spin couplings and higher-order fits to solutions of the Teukolsky
equation. We present results of Monte Carlo simulations of parameter estimation
errors and of the model errors that arise when we omit conservative corrections
from the waveform template. For a source 5000+10^6 solar mass observed with an
SNR of 1000, LISA will be able to determine the two masses to within a
fractional error of ~0.001, measure the SMBH spin magnitude, q, and the spin
magnitude of the inspiralling BH to 0.0001, 10%, respectively, and determine
the location of the source in the sky and the SMBH spin orientation to within
0.0001 steradians. For a 10+10^6 solar mass system observed with SNR of 30,
LISA will not be able to determine the spin magnitude of the inspiralling BH,
although the measurement of the other waveform parameters is not significantly
degraded by the presence of spin. The model errors which arise from ignoring
conservative corrections become significant for mass-ratios above 0.0001, but
including these corrections up to 2PN order may be sufficient to reduce these
systematic errors to an acceptable level.Comment: 24 pages, 11 figures. v2 mirrors published version in PRD. Edits in
Sections V and VI in response to comments from refere
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