4 research outputs found
Mass\unicode{x2013}spin Re-Parameterization for Rapid Parameter Estimation of Inspiral Gravitational-Wave Signals
Estimating the source parameters of gravitational waves from compact binary
coalescence(CBC) is a key analysis task in gravitational-wave astronomy. To
deal with the increasing detection rate of CBC signals, optimizing the
parameter estimation analysis is crucial. The analysis typically employs a
stochastic sampling technique such as Markov Chain Monte Carlo(MCMC), where the
source parameter space is explored and regions of high Bayesian posterior
probability density are found. One of the bottlenecks slowing down the analysis
is the non-trivial correlation between masses and spins of colliding objects,
which makes the exploration of mass\unicode{x2013}spin space extremely
inefficient. We introduce a new set of mass\unicode{x2013}spin sampling
parameters which makes the posterior distribution to be simple in the new
parameter space, regardless of the true values of the parameters. The new
parameter combinations are obtained as the principal components of the Fisher
matrix for the restricted 1.5 post-Newtonian waveform. Our re-parameterization
improves the efficiency of MCMC by a factor of for binary neutron star
with narrow-spin prior () and with broad-spin
prior (), under the assumption that the binary has spins
aligned with its orbital angular momentum.Comment: 17 pages, 12 figure
The Current Status and Future Prospects of KAGRA, the Large-Scale Cryogenic Gravitational Wave Telescope Built in the Kamioka Underground
International audienceKAGRA is a gravitational-wave (GW) detector constructed in Japan with two unique key features: It was constructed underground, and the test-mass mirrors are cooled to cryogenic temperatures. These features are not included in other kilometer-scale detectors but will be adopted in future detectors such as the Einstein Telescope. KAGRA performed its first joint observation run with GEO600 in 2020. In this observation, the sensitivity of KAGRA to GWs was inferior to that of other kilometer-scale detectors such as LIGO and Virgo. However, further upgrades to the detector are ongoing to reach the sensitivity for detecting GWs in the next observation run, which is scheduled for 2022. In this article, the current situation, sensitivity, and future perspectives are reviewed.</jats:p