16 research outputs found
First LIGO search for gravitational wave bursts from cosmic (super)strings
We report on a matched-filter search for gravitational wave bursts from
cosmic string cusps using LIGO data from the fourth science run (S4) which took
place in February and March 2005. No gravitational waves were detected in 14.9
days of data from times when all three LIGO detectors were operating. We
interpret the result in terms of a frequentist upper limit on the rate of
gravitational wave bursts and use the limits on the rate to constrain the
parameter space (string tension, reconnection probability, and loop sizes) of
cosmic string models.Comment: 11 pages, 3 figures. Replaced with version submitted to PR
Stacked Search for Gravitational Waves from the 2006 SGR 1900+14 Storm
We present the results of a LIGO search for short-duration gravitational
waves (GWs) associated with the 2006 March 29 SGR 1900+14 storm. A new search
method is used, "stacking'' the GW data around the times of individual
soft-gamma bursts in the storm to enhance sensitivity for models in which
multiple bursts are accompanied by GW emission. We assume that variation in the
time difference between burst electromagnetic emission and potential burst GW
emission is small relative to the GW signal duration, and we time-align GW
excess power time-frequency tilings containing individual burst triggers to
their corresponding electromagnetic emissions. We use two GW emission models in
our search: a fluence-weighted model and a flat (unweighted) model for the most
electromagnetically energetic bursts. We find no evidence of GWs associated
with either model. Model-dependent GW strain, isotropic GW emission energy
E_GW, and \gamma = E_GW / E_EM upper limits are estimated using a variety of
assumed waveforms. The stacking method allows us to set the most stringent
model-dependent limits on transient GW strain published to date. We find E_GW
upper limit estimates (at a nominal distance of 10 kpc) of between 2x10^45 erg
and 6x10^50 erg depending on waveform type. These limits are an order of
magnitude lower than upper limits published previously for this storm and
overlap with the range of electromagnetic energies emitted in SGR giant flares.Comment: 7 pages, 3 figure
Search for gravitational wave ringdowns from perturbed black holes in LIGO S4 data
According to general relativity a perturbed black hole will settle to a
stationary configuration by the emission of gravitational radiation. Such a
perturbation will occur, for example, in the coalescence of a black hole
binary, following their inspiral and subsequent merger. At late times the
waveform is a superposition of quasi-normal modes, which we refer to as the
ringdown. The dominant mode is expected to be the fundamental mode, l=m=2.
Since this is a well-known waveform, matched filtering can be implemented to
search for this signal using LIGO data. We present a search for gravitational
waves from black hole ringdowns in the fourth LIGO science run S4, during which
LIGO was sensitive to the dominant mode of perturbed black holes with masses in
the range of 10 Msun to 500 Msun, the regime of intermediate-mass black holes,
to distances up to 300 Mpc. We present a search for gravitational waves from
black hole ringdowns using data from S4. No gravitational wave candidates were
found; we place a 90%-confidence upper limit on the rate of ringdowns from
black holes with mass between 85 Msun and 390 Msun in the local universe,
assuming a uniform distribution of sources, of 3.2 x 10^{-5} yr^{-1} Mpc^{-3} =
1.6 x 10^{-3}yr^{-1} L_{10}^{-1}, where L_{10} is 10^{10} times the solar
blue-light luminosity.Comment: 8 pages, 6 figure
Search for gravitational waves from low mass compact binary coalescence in 186 days of LIGO's fifth science run
We report on a search for gravitational waves from coalescing compact binaries, of total mass between 2 and 35M_☉, using LIGO observations between November 14, 2006 and May 18, 2007. No gravitational-wave signals were detected. We report upper limits on the rate of compact binary coalescence as a function of total mass. The LIGO cumulative 90%-confidence rate upper limits of the binary coalescence of neutron stars, black holes and black hole-neutron star systems are 1.4 × 10^(-2), 7.3 × 10(-4) and 3.6 × 10(-3) yr(-1) L_10^(-1), respectively, where L_(10_ is 10^(10) times the blue solar luminosit
Einstein@Home search for periodic gravitational waves in early S5 LIGO data
This paper reports on an all-sky search for periodic gravitational waves from sources such as deformed isolated rapidly spinning neutron stars. The analysis uses 840 hours of data from 66 days of the fifth LIGO science run (S5). The data were searched for quasimonochromatic waves with frequencies f in the range from 50 to 1500 Hz, with a linear frequency drift ˙f (measured at the solar system barycenter) in the range −f/τ<˙f<0.1f/τ, for a minimum spin-down age τ of 1000 years for signals below 400 Hz and 8000 years above 400 Hz. The main computational work of the search was distributed over approximately 100 000 computers volunteered by the general public. This large computing power allowed the use of a relatively long coherent integration time of 30 hours while searching a large parameter space. This search extends Einstein@Home’s previous search in LIGO S4 data to about 3 times better sensitivity. No statistically significant signals were found. In the 125–225 Hz band, more than 90% of sources with dimensionless gravitational-wave strain tensor amplitude greater than 3×10−24 would have been detected
Familienkulturen in Ost- und Westdeutschland: Zum Gerechtigkeitsempfinden der Arbeitsteilung innerhalb der Partnerschaft
Einstein@Home search for periodic gravitational waves in early S5 LIGO data
This paper reports on an all-sky search for periodic gravitational waves from
sources such as deformed isolated rapidly-spinning neutron stars. The analysis
uses 840 hours of data from 66 days of the fifth LIGO science run (S5). The
data was searched for quasi-monochromatic waves with frequencies f in the range
from 50 Hz to 1500 Hz, with a linear frequency drift \dot{f} (measured at the
solar system barycenter) in the range -f/\tau < \dot{f} < 0.1 f/\tau, for a
minimum spin-down age \tau of 1000 years for signals below 400 Hz and 8000
years above 400 Hz. The main computational work of the search was distributed
over approximately 100000 computers volunteered by the general public. This
large computing power allowed the use of a relatively long coherent integration
time of 30 hours while searching a large parameter space. This search extends
Einstein@Home's previous search in LIGO S4 data to about three times better
sensitivity. No statistically significant signals were found. In the 125 Hz to
225 Hz band, more than 90% of sources with dimensionless gravitational-wave
strain tensor amplitude greater than 3e-24 would have been detected.Comment: 14 pages, 7 figure
Search for gravitational waves from low mass compact binary coalescence in 186 days of LIGO's fifth science run
We report on a search for gravitational waves from coalescing compact
binaries, of total mass between 2 and 35 Msun, using LIGO observations between
November 14, 2006 and May 18, 2007. No gravitational-wave signals were
detected. We report upper limits on the rate of compact binary coalescence as a
function of total mass. The LIGO cumulative 90%-confidence rate upper limits of
the binary coalescence of neutron stars, black holes and black hole-neutron
star systems are 1.4x10^-2, 7.3x10^-4 and 3.6x10^-3 yr^-1L_10^-1 respectively,
where L_10 is 10^10 times the blue solar luminosity