2,783 research outputs found
Erratum: Search for gravitational waves from binary black hole inspiral, merger, and ringdown (Physical Review D - Particles, Fields, Gravitation and Cosmology 2011; 83(12):122005-1-122005-20)
This paper was published online on 6 June 2011 with an omission in the Collaboration author list. S. Dwyer has been added as of 12 April 2012. The Collaboration author list is incorrect in the printed version of the journal.J. Abadie... D. J. Hosken... J. Munch... D. J. Ottaway... P. J. Veitch...et al. (LIGO Scientific Collaboration, VIRGO Collaboration
Erratum: All-sky search for gravitational-wave bursts in the first joint LIGO-GEO-Virgo run (Physical Review D - Particles, Fields, Gravitation and Cosmology - 2010: 81(10) 102001-1-102001-20)
This paper was published online on 5 May 2010 with an omission in the Collaboration author list. S. Dwyer has been added as of 12 April 2012. The Collaboration author list is incorrect in the printed version of the journalJ. Abadie... D. J. Hosken... J. Munch... D. J. Ottaway... P. J. Veitch...et al. (LIGO Scientific Collaboration, VIRGO Collaboration
GRB beaming and gravitational-wave observations
Using the observed rate of short-duration gamma-ray bursts (GRBs) it is
possible to make predictions for the detectable rate of compact binary
coalescences in gravitational-wave detectors. These estimates rely crucially on
the growing consensus that short gamma-ray bursts are associated with the
merger of two neutron stars or a neutron star and a black hole, but otherwise
make no assumptions beyond the observed rate of short GRBs. In particular, our
results do not assume coincident gravitational wave and electromagnetic
observations. We show that the non-detection of mergers in the existing
LIGO/Virgo data constrains the progenitor masses and beaming angles of
gamma-ray bursts. For future detectors, we find that the first detection of a
NS-NS binary coalescence associated with the progenitors of short GRBs is
likely to happen within the first 16 months of observation, even in the case of
a modest network of observatories (e.g., only LIGO-Hanford and LIGO-Livingston)
operating at modest sensitivities (e.g., advanced LIGO design sensitivity, but
without signal recycling mirrors), and assuming a conservative distribution of
beaming angles (e.g. all GRBs beamed at \theta=30 deg). Less conservative
assumptions reduce the waiting time until first detection to weeks to months.
Alternatively, the compact binary coalescence model of short GRBs can be ruled
out if a binary is not seen within the first two years of operation of a
LIGO-Hanford, LIGO-Livingston, and Virgo network at advanced design
sensitivity. We also demonstrate that the rate of GRB triggered sources is less
than the rate of untriggered events if \theta<30 deg, independent of the noise
curve, network configuration, and observed GRB rate. Thus the first detection
in GWs of a binary GRB progenitor is unlikely to be associated with a GRB
Swift follow-up observations of candidate gravitational-wave transient events
We present the first multi-wavelength follow-up observations of two candidate
gravitational-wave (GW) transient events recorded by LIGO and Virgo in their
2009-2010 science run. The events were selected with low latency by the network
of GW detectors and their candidate sky locations were observed by the Swift
observatory. Image transient detection was used to analyze the collected
electromagnetic data, which were found to be consistent with background.
Off-line analysis of the GW data alone has also established that the selected
GW events show no evidence of an astrophysical origin; one of them is
consistent with background and the other one was a test, part of a "blind
injection challenge". With this work we demonstrate the feasibility of rapid
follow-ups of GW transients and establish the sensitivity improvement joint
electromagnetic and GW observations could bring. This is a first step toward an
electromagnetic follow-up program in the regime of routine detections with the
advanced GW instruments expected within this decade. In that regime
multi-wavelength observations will play a significant role in completing the
astrophysical identification of GW sources. We present the methods and results
from this first combined analysis and discuss its implications in terms of
sensitivity for the present and future instruments.Comment: Submitted for publication 2012 May 25, accepted 2012 October 25,
published 2012 November 21, in ApJS, 203, 28 (
http://stacks.iop.org/0067-0049/203/28 ); 14 pages, 3 figures, 6 tables;
LIGO-P1100038; Science summary at
http://www.ligo.org/science/Publication-S6LVSwift/index.php ; Public access
area to figures, tables at
https://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=p110003
The detection efficiency of on-axis short gamma ray burst optical afterglows triggered by aLIGO/Virgo
Assuming neutron star (NS) or neutron star/stellar-mass black hole (BH)
mergers as progenitors of the short gamma ray bursts, we derive and demonstrate
a simple analysis tool for modelling the efficiency of recovering on-axis
optical afterglows triggered by a candidate gravitational wave event detected
by the Advanced LIGO and Virgo network. The coincident detection efficiency has
been evaluated for different classes of operating telescopes using observations
of gamma ray bursts. We show how the efficiency depends on the luminosity
distribution of the optical afterglows, the telescope features, and the sky
localisation of gravitational wave triggers. We estimate a plausible optical
afterglow and gravitational wave coincidence rate of 1 yr (0.1
yr) for NS-NS (NS-BH), and how this rate is scaled down in detection
efficiency by the time it takes to image the gravitational wave sky
localization and the limiting magnitude of the telescopes. For NS-NS (NS-BH) we
find maximum detection efficiencies of when the total imaging time is
less than 200 min (80 min) and the limiting magnitude fainter than 20 (21). We
show that relatively small telescopes can achieve similar detection
efficiencies to meter class facilities with similar fields of view,
only if the less sensitive instruments can respond to the trigger and image the
field within 10-15 min. The inclusion of LIGO India into the gravitational wave
observatory network will significantly reduce imaging time for telescopes with
limiting magnitudes but with modest fields of view. An optimal
coincidence search requires a global network of sensitive and fast response
wide field instruments that could effectively image relatively large
gravitational-wave sky localisations and produce transient candidates for
further photometric and spectroscopic follow-up.Comment: 6 pages, 2 figures, version 2, reference added typo correction,
Accepted by MNRA
Localizing compact binary inspirals on the sky using ground-based gravitational wave interferometers
The inspirals and mergers of compact binaries are among the most promising
events for ground-based gravitational-wave (GW) observatories. The detection of
electromagnetic (EM) signals from these sources would provide complementary
information to the GW signal. It is therefore important to determine the
ability of gravitational-wave detectors to localize compact binaries on the
sky, so that they can be matched to their EM counterparts. We use Markov Chain
Monte Carlo techniques to study sky localization using networks of ground-based
interferometers. Using a coherent-network analysis, we find that the Laser
Interferometer Gravitational Wave Observatory (LIGO)-Virgo network can localize
50% of their ~8 sigma detected neutron star binaries to better than 50 sq.deg.
with 95% confidence region. The addition of the Large Scale Cryogenic
Gravitational Wave Telescope (LCGT) and LIGO-Australia improves this to 12
sq.deg.. Using a more conservative coincident detection threshold, we find that
50% of detected neutron star binaries are localized to 13 sq.deg. using the
LIGO-Virgo network, and to 3 sq.deg. using the LIGO-Virgo-LCGT-LIGO-Australia
network. Our findings suggest that the coordination of GW observatories and EM
facilities offers great promise.Comment: 6 pages, 4 figures, 1 table, matches published version in ApJ
(incorporates referee's comments
Data analysis challenges in transient gravitational-wave astronomy
Gravitational waves are radiative solutions of space-time dynamics predicted
by Einstein's theory of General Relativity. A world-wide array of large-scale
and highly sensitive interferometric detectors constantly scrutinizes the
geometry of the local space-time with the hope to detect deviations that would
signal an impinging gravitational wave from a remote astrophysical source.
Finding the rare and weak signature of gravitational waves buried in
non-stationary and non-Gaussian instrument noise is a particularly challenging
problem. We will give an overview of the data-analysis techniques and
associated observational results obtained so far by Virgo (in Europe) and LIGO
(in the US), along with the prospects offered by the up-coming advanced
versions of those detectors.Comment: 7 pages, 5 figures, Proceedings of the ARENA'12 Conference, few minor
change
Colloquium: Multimessenger astronomy with gravitational waves and high-energy neutrinos
Many of the astrophysical sources and violent phenomena observed in our Universe are potential emitters of gravitational waves and high-energy cosmic radiation, including photons, hadrons, and presumably also neutrinos. Both gravitational waves (GW) and high-energy neutrinos (HEN) are cosmic messengers that may escape much denser media than photons. They travel unaffected over cosmological distances, carrying information from the inner regions of the astrophysical engines from which they are emitted (and from which photons and charged cosmic rays cannot reach us). For the same reasons, such messengers could also reveal new, hidden sources that have not been observed by conventional photon-based astronomy. Coincident observation of GWs and HENs may thus play a critical role in multimessenger astronomy. This is particularly true at the present time owing to the advent of a new generation of dedicated detectors: the neutrino telescopes IceCube at the South Pole and ANTARES in the Mediterranean Sea, as well as the GW interferometers Virgo in Italy and LIGO in the United States. Starting from 2007, several periods of concomitant data taking involving these detectors have been conducted. More joint data sets are expected with the next generation of advanced detectors that are to be operational by 2015, with other detectors, such as KAGRA in Japan, joining in the future. Combining information from these independent detectors can provide origin always of constraining the physical processes driving the sources and also help confirm the astrophysical origin of a GW or HEN signal in case of coincident observation. Given the complexity of the instruments, a successful joint analysis of this combined GW and HEN observational data set will be possible only if the expertise and knowledge of the data is shared between the two communities. This Colloquium aims at providing an overview of both theoretical and experimental state of the art and perspectives for GW and HEN multimessenger astronomy
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