-
the LIGO Scientific Collaboration,
the Virgo Collaboration,
J. Aasi,
J. Abadie,
B. P. Abbott,
R. Abbott,
T. D. Abbott,
M. Abernathy,
T. Accadia,
F. Acernese, [......],
M. Yvert,
A. Zadrożny,
M. Zanolin,
J. -P. Zendri, F. Zhang,
L. Zhang,
C. Zhao,
N. Zotov,
M. E. Zucker,
J. Zweizig
[show abstract]
[hide abstract]
ABSTRACT: Compact binary systems with neutron stars or black holes are one of the most
promising sources for ground-based gravitational wave detectors. Gravitational
radiation encodes rich information about source physics; thus parameter
estimation and model selection are crucial analysis steps for any detection
candidate events. Detailed models of the anticipated waveforms enable inference
on several parameters, such as component masses, spins, sky location and
distance that are essential for new astrophysical studies of these sources.
However, accurate measurements of these parameters and discrimination of models
describing the underlying physics are complicated by artifacts in the data,
uncertainties in the waveform models and in the calibration of the detectors.
Here we report such measurements on a selection of simulated signals added
either in hardware or software to the data collected by the two LIGO
instruments and the Virgo detector during their most recent joint science run,
including a "blind injection" where the signal was not initially revealed to
the collaboration. We exemplify the ability to extract information about the
source physics on signals that cover the neutron star and black hole parameter
space over the individual mass range 1 Msun - 25 Msun and the full range of
spin parameters. The cases reported in this study provide a snap-shot of the
status of parameter estimation in preparation for the operation of advanced
detectors.
04/2013;
-
The LIGO Scientific Collaboration,
the Virgo Collaboration,
J. Aasi,
J. Abadie,
B. P. Abbott,
R. Abbott,
T. D. Abbott,
M. Abernathy,
T. Accadia,
F. Acernese, [......],
M. Yvert,
A. Zadrozny,
M. Zanolin,
J. -P. Zendri, F. Zhang,
L. Zhang,
C. Zhao,
N. Zotov,
M. E. Zucker,
J. Zweizig
[show abstract]
[hide abstract]
ABSTRACT: We report a search for gravitational waves from the inspiral, merger and
ringdown of binary black holes (BBH) with total mass between 25 and 100 solar
masses, in data taken at the LIGO and Virgo observatories between July 7, 2009
and October 20, 2010. The maximum sensitive distance of the detectors over this
period for a (20,20) Msun coalescence was 300 Mpc. No gravitational wave
signals were found. We thus report upper limits on the astrophysical
coalescence rates of BBH as a function of the component masses for non-spinning
components, and also evaluate the dependence of the search sensitivity on
component spins aligned with the orbital angular momentum. We find an upper
limit at 90% confidence on the coalescence rate of BBH with non-spinning
components of mass between 19 and 28 Msun of 3.3 \times 10^-7 mergers /Mpc^3
/yr.
09/2012;
-
J. Aasi,
J. Abadie,
B. P. Abbott,
R. Abbott,
T. D. Abbott,
M. Abernathy,
T. Accadia,
F. Acernese,
C. Adams,
T. Adams, [......],
A. Zadrożny,
M. Zanolin,
J. -P. Zendri, F. Zhang,
L. Zhang,
C. Zhao,
N. Zotov,
M. E. Zucker,
J. Zweizig,
D. P. Anderson
[show abstract]
[hide abstract]
ABSTRACT: This paper presents results of an all-sky searches for periodic gravitational
waves in the frequency range [50, 1190] Hz and with frequency derivative ranges
of [-2 x 10^-9, 1.1 x 10^-10] Hz/s for the fifth LIGO science run (S5). The
novelty of the search lies in the use of a non-coherent technique based on the
Hough-transform to combine the information from coherent searches on timescales
of about one day. Because these searches are very computationally intensive,
they have been deployed on the Einstein@Home distributed computing project
infrastructure. The search presented here is about a factor 3 more sensitive
than the previous Einstein@Home search in early S5 LIGO data. The
post-processing has left us with eight surviving candidates. We show that
deeper follow-up studies rule each of them out. Hence, since no statistically
significant gravitational wave signals have been detected, we report upper
limits on the intrinsic gravitational wave amplitude h0. For example, in the
0.5 Hz-wide band at 152.5 Hz, we can exclude the presence of signals with h0
greater than 7.6 x 10^-25 with a 90% confidence level.
07/2012;
-
The ANTARES Collaboration,
the LIGO Scientific Collaboration,
the Virgo Collaboration,
S. Adrián-Martínez,
I. Al Samarai,
A. Albert,
M. André,
M. Anghinolfi,
G. Anton,
S. Anvar, [......],
M. Yvert,
A. Zadroźny,
M. Zanolin,
J. -P. Zendri, F. Zhang,
L. Zhang,
C. Zhao,
N. Zotov,
M. E. Zucker,
J. Zweizig
[show abstract]
[hide abstract]
ABSTRACT: We present the results of the first search for gravitational wave bursts
associated with high energy neutrinos. Together, these messengers could reveal
new, hidden sources that are not observed by conventional photon astronomy,
particularly at high energy. Our search uses neutrinos detected by the
underwater neutrino telescope ANTARES in its 5 line configuration during the
period January - September 2007, which coincided with the fifth and first
science runs of LIGO and Virgo, respectively. The LIGO-Virgo data were analysed
for candidate gravitational-wave signals coincident in time and direction with
the neutrino events. No significant coincident events were observed. We place
limits on the density of joint high energy neutrino - gravitational wave
emission events in the local universe, and compare them with densities of
merger and core-collapse events.
05/2012;
-
The LIGO Scientific Collaboration,
Virgo Collaboration,
J. Abadie,
B. P. Abbott,
R. Abbott,
T. D. Abbott,
M. Abernathy,
T. Accadia,
F. Acernese,
C. Adams, [......],
N. Zotov,
M. E. Zucker,
J. Zweizig,
M. S. Briggs,
V. Connaughton,
K. C. Hurley,
P. A. Jenke,
A. von Kienlin,
A. Rau,
X. -L. Zhang
[show abstract]
[hide abstract]
ABSTRACT: We present the results of a search for gravitational waves associated with
154 gamma-ray bursts (GRBs) that were detected by satellite-based gamma-ray
experiments in 2009-2010, during the sixth LIGO science run and the second and
third Virgo science runs. We perform two distinct searches: a modeled search
for coalescences of either two neutron stars or a neutron star and black hole;
and a search for generic, unmodeled gravitational-wave bursts. We find no
evidence for gravitational-wave counterparts, either with any individual GRB in
this sample or with the population as a whole. For all GRBs we place lower
bounds on the distance to the progenitor, under the optimistic assumption of a
gravitational-wave emission energy of 10^-2 M c^2 at 150 Hz, with a median
limit of 17 Mpc. For short hard GRBs we place exclusion distances on binary
neutron star and neutron star-black hole progenitors, using astrophysically
motivated priors on the source parameters, with median values of 16 Mpc and 28
Mpc respectively. These distance limits, while significantly larger than for a
search that is not aided by GRB satellite observations, are not large enough to
expect a coincidence with a GRB. However, projecting these exclusions to the
sensitivities of Advanced LIGO and Virgo, which should begin operation in 2015,
we find that the detection of gravitational waves associated with GRBs will
become quite possible.
05/2012;
-
P. A. Evans,
J. K. Fridriksson,
N. Gehrels,
J. Homan,
J. P. Osborne,
M. Siegel,
A. Beardmore,
P. Handbauer,
J. Gelbord,
J. A. Kennea, [......],
M. Yvert,
A. Zadrozny,
M. Zanolin,
J. -P. Zendri, F. Zhang,
L. Zhang,
C. Zhao,
N. Zotov,
M. E. Zucker,
J. Zweizig
[show abstract]
[hide abstract]
ABSTRACT: 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.
05/2012;
-
J. Aasi,
J. Abadie,
B. P. Abbott,
R. Abbott,
T. D. Abbott,
M. Abernathy,
T. Accadia,
F. Acernese,
C. Adams,
T. Adams, [......],
M. Yvert,
A. Zadrożny,
M. Zanolin,
J. -P. Zendri, F. Zhang,
L. Zhang,
C. Zhao,
N. Zotov,
M. E. Zucker,
J. Zweizig
[show abstract]
[hide abstract]
ABSTRACT: Between 2007 and 2010 Virgo collected data in coincidence with the LIGO and
GEO gravitational-wave (GW) detectors. These data have been searched for GWs
emitted by cataclysmic phenomena in the universe, by non-axisymmetric rotating
neutron stars or from a stochastic background in the frequency band of the
detectors. The sensitivity of GW searches is limited by noise produced by the
detector or its environment. It is therefore crucial to characterize the
various noise sources in a GW detector. This paper reviews the Virgo detector
noise sources, noise propagation, and conversion mechanisms which were
identified in the three first Virgo observing runs. In many cases, these
investigations allowed us to mitigate noise sources in the detector, or to
selectively flag noise events and discard them from the data. We present
examples from the joint LIGO-GEO-Virgo GW searches to show how well noise
transients and narrow spectral lines have been identified and excluded from the
Virgo data. We also discuss how detector characterization can improve the
astrophysical reach of gravitational-wave searches.
03/2012;
-
the LIGO Scientific Collaboration,
the Virgo Collaboration,
J. Abadie,
B. P. Abbott,
R. Abbott,
T. D. Abbott,
M. Abernathy,
T. Accadia,
F. Acernese,
C. Adams, [......],
A. Zadrozny,
M. Zanolin,
J. -P. Zendri,
F. Zhang,
L. Zhang,
W. Zhang,
C. Zhao,
N. Zotov,
M. E. Zucker,
J. Zweizig
[show abstract]
[hide abstract]
ABSTRACT: We present results from a search for gravitational-wave bursts in the data
collected by the LIGO and Virgo detectors between July 7, 2009 and October 20,
2010: data are analyzed when at least two of the three LIGO-Virgo detectors are
in coincident operation, with a total observation time of 207 days. The
analysis searches for transients of duration < 1 s over the frequency band
64-5000 Hz, without other assumptions on the signal waveform, polarization,
direction or occurrence time. All identified events are consistent with the
expected accidental background. We set frequentist upper limits on the rate of
gravitational-wave bursts by combining this search with the previous LIGO-Virgo
search on the data collected between November 2005 and October 2007. The upper
limit on the rate of strong gravitational-wave bursts at the Earth is 1.3
events per year at 90% confidence. We also present upper limits on source rate
density per year and Mpc^3 for sample populations of standard-candle sources.
As in the previous joint run, typical sensitivities of the search in terms of
the root-sum-squared strain amplitude for these waveforms lie in the range 5
10^-22 Hz^-1/2 to 1 10^-20 Hz^-1/2. The combination of the two joint runs
entails the most sensitive all-sky search for generic gravitational-wave bursts
and synthesizes the results achieved by the initial generation of
interferometric detectors.
02/2012;
-
the LIGO Scientific Collaboration,
the Virgo Collaboration,
J. Abadie,
B. P. Abbott,
R. Abbott,
T. D. Abbott,
M. Abernathy,
T. Accadia,
F. Acernese,
C. Adams, [......],
A. Zadrozny,
M. Zanolin,
J. -P. Zendri,
F. Zhang,
L. Zhang,
W. Zhang,
C. Zhao,
N. Zotov,
M. E. Zucker,
J. Zweizig
[show abstract]
[hide abstract]
ABSTRACT: We present the results of a weakly modeled burst search for gravitational
waves from mergers of non-spinning intermediate mass black holes (IMBH) in the
total mass range 100--450 solar masses and with the component mass ratios
between 1:1 and 4:1. The search was conducted on data collected by the LIGO and
Virgo detectors between November of 2005 and October of 2007. No plausible
signals were observed by the search which constrains the astrophysical rates of
the IMBH mergers as a function of the component masses. In the most efficiently
detected bin centered on 88+88 solar masses, for non-spinning sources, the rate
density upper limit is 0.13 per Mpc^3 per Myr at the 90% confidence level.
01/2012;
-
J. Abadie,
B. P. Abbott,
R. Abbott,
T. D. Abbott,
M. Abernathy,
T. Accadia,
F. Acernese,
C. Adams,
R. Adhikari,
C. Affeldt, [......],
A. Zadroźny,
M. Zanolin,
J. -P. Zendri,
F. Zhang,
L. Zhang,
W. Zhang,
C. Zhao,
N. Zotov,
M. E. Zucker,
J. Zweizig
[show abstract]
[hide abstract]
ABSTRACT: A stochastic background of gravitational waves is expected to arise from a
superposition of many incoherent sources of gravitational waves, of either
cosmological or astrophysical origin. This background is a target for the
current generation of ground-based detectors. In this article we present the
first joint search for a stochastic background using data from the LIGO and
Virgo interferometers. In a frequency band of 600-1000 Hz, we obtained a 95%
upper limit on the amplitude of $\Omega_{\rm GW}(f) = \Omega_3 (f/900
\mathrm{Hz})^3$, of $\Omega_3 < 0.33$, assuming a value of the Hubble parameter
of $h_{100}=0.72$. These new limits are a factor of seven better than the
previous best in this frequency band.
12/2011;
-
A Heptonstall,
M A Barton,
A Bell,
G Cagnoli,
C A Cantley,
D R M Crooks,
A Cumming,
A Grant,
G D Hammond,
G M Harry,
J Hough,
R Jones, D Kelley,
R Kumar,
I W Martin,
N A Robertson,
S Rowan,
K A Strain,
K Tokmakov,
M van Veggel
[show abstract]
[hide abstract]
ABSTRACT: In 2000 the first mirror suspensions to use a quasi-monolithic final stage were installed at the GEO600 detector site outside Hannover, pioneering the use of fused silica suspension fibers in long baseline interferometric detectors to reduce suspension thermal noise. Since that time, development of the production methods of fused silica fibers has continued. We present here a review of a novel CO(2) laser-based fiber pulling machine developed for the production of fused silica suspensions for the next generation of interferometric gravitational wave detectors and for use in experiments requiring low thermal noise suspensions. We discuss tolerances, strengths, and thermal noise performance requirements for the next generation of gravitational wave detectors. Measurements made on fibers produced using this machine show a 0.8% variation in vertical stiffness and 0.05% tolerance on length, with average strengths exceeding 4 GPa, and mechanical dissipation which meets the requirements for Advanced LIGO thermal noise performance.
The Review of scientific instruments 01/2011; 82(1):011301. · 1.52 Impact Factor
-
J. K. Harmon,
S. J. Ostro,
L. A. M. Benner,
K. D. Rosema,
R. F. Jurgens,
R. Winkler,
D. K. Yeomans,
D. Choate,
R. Cormier,
J. D. Giorgini,
D. L. Mitchell,
P. W. Chodas,
R. Rose, D. Kelley,
M. A. Slade,
M. L. Thomas
[show abstract]
[hide abstract]
ABSTRACT: Radar observations of comet Hyakutake (C/1996 B2) made at the Goldstone Deep Space Communications Complex in California have
detected echoes from the nucleus and from large grains in the inner coma. The nucleus of this bright comet was estimated to
be only 2 to 3 kilometers in diameter. Models of the coma echo indicate backscatter from porous, centimeter-size grains ejected
anisotropically at velocities of tens of meters per second. The radar observations suggest that a comet's activity may be
a poor indicator of its size and provide evidence that large grains constitute an important component of the mass loss from
a typical active comet.
Science 12/1997; 278(5345):1921-1924. · 31.20 Impact Factor
-
R.S. Hudson,
S.J. Ostro,
R.F. Jurgens,
K.D. Rosema,
J.D. Giorgini,
R. Winkler,
R. Rose,
D. Choate,
R.A. Cormier,
C.R. Franck, [......],
D.L. Mitchell,
P.W. Chodas,
D.K. Yeomans,
D.J. Scheeres,
P. Palmer,
A. Zaitsev,
Y. Koyama,
A. Nakamura,
A.W. Harris,
M.N. Meshkov
[show abstract]
[hide abstract]
ABSTRACT: We report 8510-MHz (3.5-cm) radar observations of the Earth-crossing asteroid (ECA) 6489 Golevka (1991 JX) obtained between June 3 and June 15, 1995, at Goldstone, the Very Large Array and the Evpatoria (Ukraine) and Kashima (Japan) radio antennas. One-dimensional Doppler spectra are used to estimate the object's convex hull, refine the ephemeris, and yield four possible pole directions. Three-dimensional modeling using two-dimensional delay-Doppler images and published lightcurves unambiguously defines the pole and reveals an extraordinarily angular shape with flat sides, sharp edges and corners, and peculiar concavities. The equivalent diameter of the object is 530±30 m, with moments of inertia about the (long, intermediate, short) axes proportional to (1.00, 1.38, 1.39) ±0.1. The asteroid's pole direction is λ=202±5°, β=−45±5°, and its sidereal period is P=6.0289±0.0001 h.The asteroid's circular polarization ratio, SC/OC=0.23±0.02, is lower than the average for radar-detected near-Earth asteroids and reveals only a modest degree of near-surface roughness at scales near the 3.5-cm wavelength. However, the approximately Lambertian radar scattering law implies considerable surface roughness at larger scales. The asteroid's radar scattering law is modeled as ρcosnθ, with ρ=0.25±0.12 and n=1.7±0.7 giving an equivalent spherical albedo of 0.18±0.09. This value is in the middle of the distribution of albedos of S-class asteroid's previously imaged by radar. The Hapke parameters describing the object's optical scattering properties are w=0.173±0.006, h=0.024±0.012, B0=1.03±0.45, g=−0.34±0.02, and =20±5°. Both the optical and the radar scattering properties are consistent with those of a typical S-class asteroid.Goldstone-VLA plane-of-sky images do not resolve the asteroid but do provide astrometry with uncertainties less than 0.1 arcsec. Integration of an orbit based on all available radar and optical astrometry shows that Golevka has an insignificant probability of collision with any planet during at least the next nine centuries.We investigate Golevka's dynamical environment, assuming uniform density. Some areas of the surface are characterized by large enough slopes that we expect that they are exposed, solid, monolithic rock.
Icarus.
-
A. Heptonstall,
M. A. Barton,
A Bell,
G. Cagnoli,
C. A. Cantley,
D. R. M. Crooks,
A. Cumming,
A Grant,
G. D. Hammond,
G. M. Harry,
J. Hough,
R Jones, D. Kelley,
R Kumar,
I. W. Martin,
N A Robertson,
S. Rowan,
K. A. Strain,
K. Tokmakov,
M. Van Veggel
[show abstract]
[hide abstract]
ABSTRACT: In 2000 the first mirror suspensions to use a quasi-monolithic final stage were installed at the GEO600 detector site outside Hannover, pioneering the use of fused silica suspension fibers in long baseline interferometric detectors to reduce suspension thermal noise. Since that time, development of the production methods of fused silica fibers has continued. We present here a review of a novel CO_2 laser-based fiber pulling machine developed for the production of fused silica suspensions for the next generation of interferometric gravitational wave detectors and for use in experiments requiring low thermal noise suspensions. We discuss tolerances, strengths, and thermal noise performance requirements for the next generation of gravitational wave detectors. Measurements made on fibers produced using this machine show a 0.8% variation in vertical stiffness and 0.05% tolerance on length, with average strengths exceeding 4 GPa, and mechanical dissipation which meets the requirements for Advanced LIGO thermal noise performance.
-
R.S. Hudson,
S.J. Ostro,
R.F. Jurgens,
K.D. Rosema,
J.D. Giorgini,
R. Winkler,
R. Rose,
D. Choate,
R.A. Cormier,
C.R. Franck, [......],
D.L. Mitchell,
P.W. Chodas,
D.K. Yeomans,
D.J. Scheeres,
P. Palmer,
A. Zaitsev,
Y. Koyama,
A. Nakamura,
A.W. Harris,
M.N. Meshkov
Icarus. 148(2000-1):37-51.
