ORCID Profile
0000-0002-8659-5898
Current Organisation
Georgia Institute of Technology
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Publisher: IOP Publishing
Date: 27-04-2020
Publisher: American Physical Society (APS)
Date: 13-12-2022
Publisher: Oxford University Press (OUP)
Date: 29-01-2022
Abstract: Radio pulsar glitches probe far-from-equilibrium processes involving stress accumulation and relaxation in neutron star interiors. Previous studies of glitch rates have focused on in idual pulsars with as many recorded glitches as possible. In this work, we analyse glitch rates using all available data including objects that have glitched never or once. We assume the glitch rate follows a homogeneous Poisson process, and therefore exclude pulsars that exhibit quasiperiodic glitching behaviour. Calculating relevant Bayes factors shows that a model in which the glitch rate λ scales as a power of the characteristic age τ is preferred over models that depend arbitrarily on powers of the spin frequency ν and/or its time derivative $\\dot{\\nu }$. For λ = A(τ/τref)−γ, where τref = 1 yr is a reference time, the posterior distributions are unimodal with $A=0.0066_{-0.002}^{+0.003}\\ \\rm {yr}^{-1}$ and $\\gamma =0.27_{-0.03}^{+0.03}$. Importantly, the data exclude with 99 per cent confidence the possibility γ = 1 canvassed in the literature. When objects with zero-recorded glitches are included, the age-based rate law is still preferred and the posteriors change to give $A=0.0099_{-0.003}^{+0.004}\\ \\rm {yr}^{-1}$ and $\\gamma =0.31_{-0.03}^{+0.03}$. The updated estimates still support increased glitch activity for younger pulsars, while demonstrating that the large number of objects with zero glitches contain important statistical information about the rate, provided that they are part of the same population as opposed to a disjoint population which never glitches for some unknown physical reason.
Publisher: IOP Publishing
Date: 24-11-2022
Abstract: Data from ground-based gravitational-wave detectors contains numerous short-duration instrumental artifacts, called ‘glitches’. The high rate of these artifacts in turn results in a significant fraction of gravitational-wave signals from compact binary coalescences overlapping glitches. In LIGO-Virgo’s third observing run, ≈20% of gravitational-wave source candidates required some form of mitigation due to glitches. This was the first observing run where glitch subtraction was included as a part of LIGO-Virgo-KAGRA data analysis methods for a large fraction of detected gravitational-wave events. This work describes the methods to identify glitches, the decision process for deciding if mitigation was necessary, and the two algorithms, BayesWave and gwsubtract , that were used to model and subtract glitches. Through case studies of two events, GW190424_180648 and GW200129_065458, we evaluate the effectiveness of the glitch subtraction, compare the statistical uncertainties in the relevant glitch models, and identify potential limitations in these glitch subtraction methods. We finally outline the lessons learned from this first-of-its-kind effort for future observing runs.
Publisher: American Physical Society (APS)
Date: 21-10-2020
Publisher: American Physical Society (APS)
Date: 02-02-2021
Publisher: American Physical Society (APS)
Date: 22-09-2020
Publisher: American Physical Society (APS)
Date: 16-03-2021
Publisher: Oxford University Press (OUP)
Date: 21-09-2020
Abstract: Gravitational waves provide a unique tool for observational astronomy. While the first LIGO–Virgo catalogue of gravitational-wave transients (GWTC-1) contains 11 signals from black hole and neutron star binaries, the number of observations is increasing rapidly as detector sensitivity improves. To extract information from the observed signals, it is imperative to have fast, flexible, and scalable inference techniques. In a previous paper, we introduced bilby: a modular and user-friendly Bayesian inference library adapted to address the needs of gravitational-wave inference. In this work, we demonstrate that bilby produces reliable results for simulated gravitational-wave signals from compact binary mergers, and verify that it accurately reproduces results reported for the 11 GWTC-1 signals. Additionally, we provide configuration and output files for all analyses to allow for easy reproduction, modification, and future use. This work establishes that bilby is primed and ready to analyse the rapidly growing population of compact binary coalescence gravitational-wave signals.
No related grants have been discovered for Margaret Millhouse.