50 research outputs found
GWTC-3: Compact Binary Coalescences Observed by LIGO and Virgo during the Second Part of the Third Observing Run
The third Gravitational-Wave Transient Catalog (GWTC-3) describes signals detected with Advanced LIGO and Advanced Virgo up to the end of their third observing run. Updating the previous GWTC-2.1, we present candidate gravitational waves from compact binary coalescences during the second half of the third observing run (O3b) between 1 November 2019, 15∶00 Coordinated Universal Time (UTC) and 27 March 2020, 17∶00 UTC. There are 35 compact binary coalescence candidates identified by at least one of our search algorithms with a probability of astrophysical origin pastro>0.5. Of these, 18 were previously reported as low-latency public alerts, and 17 are reported here for the first time. Based upon estimates for the component masses, our O3b candidates with pastro>0.5 are consistent with gravitational-wave signals from binary black holes or neutron-star-black-hole binaries, and we identify none from binary neutron stars. However, from the gravitational-wave data alone, we are not able to measure matter effects that distinguish whether the binary components are neutron stars or black holes. The range of inferred component masses is similar to that found with previous catalogs, but the O3b candidates include the first confident observations of neutron-star-black-hole binaries. Including the 35 candidates from O3b in addition to those from GWTC-2.1, GWTC-3 contains 90 candidates found by our analysis with pastro>0.5 across the first three observing runs. These observations of compact binary coalescences present an unprecedented view of the properties of black holes and neutron stars
Search for Gravitational Waves Associated with Fast Radio Bursts Detected by CHIME/FRB during the LIGO-Virgo Observing Run O3a
We search for gravitational-wave (GW) transients associated with fast radio bursts (FRBs) detected by the Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst Project, during the first part of the third observing run of Advanced LIGO and Advanced Virgo (2019 April 1 15:00 UTC-2019 October 1 15:00 UTC). Triggers from 22 FRBs were analyzed with a search that targets both binary neutron star (BNS) and neutron star-black hole (NSBH) mergers. A targeted search for generic GW transients was conducted on 40 FRBs. We find no significant evidence for a GW association in either search. Given the large uncertainties in the distances of our FRB sample, we are unable to exclude the possibility of a GW association. Assessing the volumetric event rates of both FRB and binary mergers, an association is limited to 15% of the FRB population for BNS mergers or 1% for NSBH mergers. We report 90% confidence lower bounds on the distance to each FRB for a range of GW progenitor models and set upper limits on the energy emitted through GWs for a range of emission scenarios. We find values of order 1051-1057 erg for models with central GW frequencies in the range 70-3560 Hz. At the sensitivity of this search, we find these limits to be above the predicted GW emissions for the models considered. We also find no significant coincident detection of GWs with the repeater, FRB 20200120E, which is the closest known extragalactic FRB
Constraints on the Cosmic Expansion History from GWTC-3
We use 47 gravitational wave sources from the Third LIGO-Virgo-Kamioka Gravitational Wave Detector Gravitational Wave Transient Catalog (GWTC-3) to estimate the Hubble parameter H(z), including its current value, the Hubble constant H0. Each gravitational wave (GW) signal provides the luminosity distance to the source, and we estimate the corresponding redshift using two methods: the redshifted masses and a galaxy catalog. Using the binary black hole (BBH) redshifted masses, we simultaneously infer the source mass distribution and H(z). The source mass distribution displays a peak around 34Me, followed by a drop-off. Assuming this mass scale does not evolve with the redshift results in a H(z) measurement, yielding H0 = 68+12-8 km s-1 Mpc-1 (68% credible interval) when combined with the H0 measurement from GW170817 and its electromagnetic counterpart. This represents an improvement of 17% with respect to the H0 estimate from GWTC-1. The second method associates each GW event with its probable host galaxy in the catalog GLADE+, statistically marginalizing over the redshifts of each event's potential hosts. Assuming a fixed BBH population, we estimate a value of H0 = 68+8-6 km s-1 Mpc-1 with the galaxy catalog method, an improvement of 42% with respect to our GWTC-1 result and 20% with respect to recent H0 studies using GWTC-2 events. However, we show that this result is strongly impacted by assumptions about the BBH source mass distribution; the only event which is not strongly impacted by such assumptions (and is thus informative about H0) is the well-localized event GW190814
Search for continuous gravitational waves from 20 accreting millisecond x-ray pulsars in O3 LIGO data
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GW190814: Gravitational Waves from the Coalescence of a 23 Solar Mass Black Hole with a 2.6 Solar Mass Compact Object
We report the observation of a compact binary coalescence involving a 22.2 -
24.3 black hole and a compact object with a mass of 2.50 - 2.67
(all measurements quoted at the 90 credible level). The
gravitational-wave signal, GW190814, was observed during LIGO's and Virgo's
third observing run on August 14, 2019 at 21:10:39 UTC and has a
signal-to-noise ratio of 25 in the three-detector network. The source was
localized to 18.5 deg at a distance of Mpc; no
electromagnetic counterpart has been confirmed to date. The source has the most
unequal mass ratio yet measured with gravitational waves,
, and its secondary component is either the lightest
black hole or the heaviest neutron star ever discovered in a double
compact-object system. The dimensionless spin of the primary black hole is
tightly constrained to . Tests of general relativity reveal no
measurable deviations from the theory, and its prediction of higher-multipole
emission is confirmed at high confidence. We estimate a merger rate density of
1-23 Gpc yr for the new class of binary coalescence sources that
GW190814 represents. Astrophysical models predict that binaries with mass
ratios similar to this event can form through several channels, but are
unlikely to have formed in globular clusters. However, the combination of mass
ratio, component masses, and the inferred merger rate for this event challenges
all current models for the formation and mass distribution of compact-object
binaries
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Observation of Gravitational Waves from Two Neutron Star-Black Hole Coalescences
We report the observation of gravitational waves from two compact binary
coalescences in LIGO's and Virgo's third observing run with properties
consistent with neutron star-black hole (NSBH) binaries. The two events are
named GW200105_162426 and GW200115_042309, abbreviated as GW200105 and
GW200115; the first was observed by LIGO Livingston and Virgo, and the second
by all three LIGO-Virgo detectors. The source of GW200105 has component masses
and , whereas the
source of GW200115 has component masses and
(all measurements quoted at the 90% credible
level). The probability that the secondary's mass is below the maximal mass of
a neutron star is 89%-96% and 87%-98%, respectively, for GW200105 and GW200115,
with the ranges arising from different astrophysical assumptions. The source
luminosity distances are Mpc and Mpc,
respectively. The magnitude of the primary spin of GW200105 is less than 0.23
at the 90% credible level, and its orientation is unconstrained. For GW200115,
the primary spin has a negative spin projection onto the orbital angular
momentum at 88% probability. We are unable to constrain spin or tidal
deformation of the secondary component for either event. We infer a NSBH merger
rate density of when
assuming GW200105 and GW200115 are representative of the NSBH population, or
under the assumption of
a broader distribution of component masses
Search for gravitational waves associated with gamma-ray bursts detected by Fermi and Swift during the LIGO–Virgo run O3b
We search for gravitational-wave signals associated with gamma-ray bursts (GRBs) detected by the Fermi and Swift satellites during the second half of the third observing run of Advanced LIGO and Advanced Virgo (2019 November 1 15:00 UTC–2020 March 27 17:00 UTC). We conduct two independent searches: a generic gravitational-wave transients search to analyze 86 GRBs and an analysis to target binary mergers with at least one neutron star as short GRB progenitors for 17 events. We find no significant evidence for gravitational-wave signals associated with any of these GRBs. A weighted binomial test of the combined results finds no evidence for subthreshold gravitational-wave signals associated with this GRB ensemble either. We use several source types and signal morphologies during the searches, resulting in lower bounds on the estimated distance to each GRB. Finally, we constrain the population of low-luminosity short GRBs using results from the first to the third observing runs of Advanced LIGO and Advanced Virgo. The resulting population is in accordance with the local binary neutron star merger rate