ORCID Profile
0000-0003-3763-1386
Current Organisation
Monash University
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Astronomical and Space Sciences | General Relativity and Gravitational Waves | Astronomical and Space Instrumentation | Astronomical sciences | High Energy Astrophysics; Cosmic Rays | Cosmology and extragalactic astronomy | General relativity and gravitational waves | Cosmology and Extragalactic Astronomy | Space instrumentation | Astronomical and Space Sciences not elsewhere classified | Lasers and Quantum Electronics | Classical and Physical Optics | Lasers and quantum electronics |
Expanding Knowledge in the Physical Sciences | Expanding Knowledge in the Information and Computing Sciences | Scientific Instruments | Expanding Knowledge in Engineering | Network Infrastructure Equipment | Command, Control and Communications | Expanding Knowledge in Technology
Publisher: American Astronomical Society
Date: 23-06-2017
Publisher: Springer Science and Business Media LLC
Date: 06-2021
Publisher: American Physical Society (APS)
Date: 21-01-2021
Publisher: Oxford University Press (OUP)
Date: 09-02-2012
Publisher: American Physical Society (APS)
Date: 10-03-2016
Publisher: American Physical Society (APS)
Date: 05-11-2018
Publisher: Cambridge University Press (CUP)
Date: 07-2007
DOI: 10.1017/S1446181100012670
Abstract: Formulating a dust-filled spherically symmetric metric utilizing the 3 + 1 formalism for general relativity, we show that the metric coefficients are completely determined by the matter distribution throughout the spacetime. Furthermore, the metric describes both inhomogeneous dust regions and also vacuum regions in a single coordinate patch, thus alleviating the need for complicated matching schemes at the interfaces. In this way, the system is established as an initial boundary value problem, which has many benefits for its numerical evolution. We show the dust part of the metric is equivalent to the class of Lemaitre-Tolman-Bondi (LTB) metrics under a coordinate transformation. In this coordinate system, shell crossing singularities (SCS) are exhibited as fluid shock waves, and we therefore discuss possibilities for the dynamical extension of shell crossings through the initial point of formation by borrowing methods from classical fluid dynamics. This paper fills a void in the present literature associated with these collapse models by fully developing the formalism in great detail. Furthermore, the applications provide ex les of the benefits of the present model.
Publisher: Oxford University Press (OUP)
Date: 24-12-2017
Publisher: Oxford University Press (OUP)
Date: 06-07-2008
Publisher: American Physical Society (APS)
Date: 12-10-2006
Publisher: American Physical Society (APS)
Date: 14-11-2017
Publisher: American Physical Society (APS)
Date: 12-09-2022
Publisher: American Physical Society (APS)
Date: 05-08-2016
Publisher: Oxford University Press (OUP)
Date: 04-09-2008
Publisher: American Astronomical Society
Date: 30-04-2021
Abstract: The joint observation of the gravitational-wave (GW) and electromagnetic (EM) signal from the binary neutron-star merger GW170817 allowed for a new independent measurement of the Hubble constant H 0 , albeit with an uncertainty of about 15% at 1 σ . Observations of similar sources with a network of future detectors will allow for more precise measurements of H 0 . These, however, are currently largely limited by the intrinsic degeneracy between the luminosity distance and the inclination of the source in the GW signal. We show that the higher-order modes in gravitational waves can be used to break this degeneracy in astrophysical parameter estimation in both the inspiral and post-merger phases of a neutron star merger. We show that for systems at distances similar to GW170817, this method enables percent-level measurements of H 0 with a single detection. This would permit the study of time variations and spatial anisotropies of H 0 with unprecedented precision. We investigate how different network configurations affect measurements of H 0 , and discuss the implications in terms of science drivers for the proposed 2.5- and third-generation GW detectors. Finally, we show that the precision of H 0 measured with these future observatories will be solely limited by redshift measurements of EM counterparts.
Publisher: Springer International Publishing
Date: 10-11-2014
Publisher: Oxford University Press (OUP)
Date: 20-10-2014
Publisher: American Astronomical Society
Date: 26-05-2022
Abstract: Ultralight bosons are a proposed solution to outstanding problems in cosmology and particle physics: they provide a dark-matter candidate while potentially explaining the strong charge-parity problem. If they exist, ultralight bosons can interact with black holes through the superradiant instability. In this work we explore the consequences of this instability on the evolution of hierarchical black holes within dense stellar clusters. By reducing the spin of in idual black holes, superradiance reduces the recoil velocity of merging binary black holes, which, in turn, increases the retention fraction of hierarchical merger remnants. We show that the existence of ultralight bosons with mass 2 × 10 −14 ≲ μ /eV ≲ 2 × 10 −13 would lead to an increased rate of hierarchical black hole mergers in nuclear star clusters. An ultralight boson in this energy range would result in up to ≈60% more present-day nuclear star clusters supporting hierarchical growth. The presence of an ultralight boson can also double the rate of intermediate-mass black hole mergers to ≈0.08 Gpc −3 yr −1 in the local universe. These results imply that a select range of ultralight boson masses can have far-reaching consequences for the population of black holes in dense stellar environments. Future studies into black hole cluster populations and the spin distribution of hierarchically formed black holes will test this scenario.
Publisher: Wiley
Date: 04-10-2016
Publisher: American Physical Society (APS)
Date: 18-03-2020
Publisher: American Physical Society (APS)
Date: 15-02-2023
Publisher: American Astronomical Society
Date: 07-04-2017
Publisher: American Astronomical Society
Date: 21-08-2018
Publisher: American Astronomical Society
Date: 14-03-2022
Abstract: Quasiperiodic oscillations (QPOs) are an important key to understand the dynamic behavior of astrophysical objects during transient events like gamma-ray bursts, solar flares, and magnetar flares. Searches for QPOs often use the periodogram of the time series and perform spectral density estimation using a Whittle likelihood function. However, the Whittle likelihood is only valid if the time series is stationary since the frequency bins are otherwise not statistically independent. We show that if time series are nonstationary, the significance of QPOs can be highly overestimated and estimates of the central frequencies and QPO widths can be overconstrained. The effect occurs if the QPO is only present for a fraction of the time series and the noise level is varying throughout the time series. This can occur, for ex le, if background noise from before or after the transient is included in the time series or if the low-frequency noise profile varies strongly over the time series. Thus, we highlight the importance of careful segment selection prior to the analysis. We confirm the presence of this bias in previously reported results from solar flare data and show that significance can be highly overstated. Finally, we provide some suggestions that help identify whether an analysis is affected by this bias.
Publisher: Cambridge University Press (CUP)
Date: 2020
DOI: 10.1017/PASA.2020.39
Abstract: Gravitational waves from coalescing neutron stars encode information about nuclear matter at extreme densities, inaccessible by laboratory experiments. The late inspiral is influenced by the presence of tides, which depend on the neutron star equation of state. Neutron star mergers are expected to often produce rapidly rotating remnant neutron stars that emit gravitational waves. These will provide clues to the extremely hot post-merger environment. This signature of nuclear matter in gravitational waves contains most information in the 2–4 kHz frequency band, which is outside of the most sensitive band of current detectors. We present the design concept and science case for a Neutron Star Extreme Matter Observatory (NEMO): a gravitational-wave interferometer optimised to study nuclear physics with merging neutron stars. The concept uses high-circulating laser power, quantum squeezing, and a detector topology specifically designed to achieve the high-frequency sensitivity necessary to probe nuclear matter using gravitational waves. Above 1 kHz, the proposed strain sensitivity is comparable to full third-generation detectors at a fraction of the cost. Such sensitivity changes expected event rates for detection of post-merger remnants from approximately one per few decades with two A+ detectors to a few per year and potentially allow for the first gravitational-wave observations of supernovae, isolated neutron stars, and other exotica.
Publisher: American Astronomical Society
Date: 23-10-2020
Publisher: Springer Science and Business Media LLC
Date: 26-04-2018
DOI: 10.1007/S41114-018-0012-9
Abstract: We present possible observing scenarios for the Advanced LIGO, Advanced Virgo and KAGRA gravitational-wave detectors over the next decade, with the intention of providing information to the astronomy community to facilitate planning for multi-messenger astronomy with gravitational waves. We estimate the sensitivity of the network to transient gravitational-wave signals, and study the capability of the network to determine the sky location of the source. We report our findings for gravitational-wave transients, with particular focus on gravitational-wave signals from the inspiral of binary neutron star systems, which are the most promising targets for multi-messenger astronomy. The ability to localize the sources of the detected signals depends on the geographical distribution of the detectors and their relative sensitivity, and $$90\\%$$ 90 % credible regions can be as large as thousands of square degrees when only two sensitive detectors are operational. Determining the sky position of a significant fraction of detected signals to areas of 5– $$20~\\mathrm {deg}^2$$ 20 deg 2 requires at least three detectors of sensitivity within a factor of $$\\sim 2$$ ∼ 2 of each other and with a broad frequency bandwidth. When all detectors, including KAGRA and the third LIGO detector in India, reach design sensitivity, a significant fraction of gravitational-wave signals will be localized to a few square degrees by gravitational-wave observations alone.
Publisher: Oxford University Press (OUP)
Date: 23-08-2016
Publisher: American Physical Society (APS)
Date: 19-10-2016
Publisher: SAGE Publications
Date: 06-12-2021
Publisher: Oxford University Press (OUP)
Date: 18-07-2013
Publisher: American Physical Society (APS)
Date: 08-11-2013
Publisher: IOP Publishing
Date: 12-04-2017
Publisher: American Physical Society (APS)
Date: 22-01-2020
Publisher: American Physical Society (APS)
Date: 08-2018
Publisher: Oxford University Press (OUP)
Date: 12-12-2012
Publisher: American Physical Society (APS)
Date: 25-01-2007
Publisher: American Astronomical Society
Date: 04-2019
Publisher: Oxford University Press (OUP)
Date: 10-2018
Publisher: Oxford University Press (OUP)
Date: 22-08-2011
Publisher: American Physical Society (APS)
Date: 04-05-2017
Publisher: American Physical Society (APS)
Date: 06-07-2021
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.
Publisher: American Astronomical Society
Date: 11-2021
Publisher: Oxford University Press (OUP)
Date: 10-2008
Publisher: American Physical Society (APS)
Date: 17-09-2018
Publisher: American Astronomical Society
Date: 09-2022
Abstract: Orbital eccentricity is a key signature of dynamical binary black hole formation. The gravitational waves from a coalescing binary contain information about its orbital eccentricity, which may be measured if the binary retains sufficient eccentricity near merger. Dedicated waveforms are required to measure eccentricity. Several models have been put forward, and show good agreement with numerical relativity at the level of a few percent or better. However, there are multiple ways to define eccentricity for inspiralling systems, and different models internally use different definitions of eccentricity, making it difficult to compare eccentricity measurements directly. In this work, we systematically compare two eccentric waveform models, SEOBNRE and TEOBResumS , by developing a framework to translate between different definitions of eccentricity. This mapping is constructed by minimizing the relative mismatch between the two models over eccentricity and reference frequency, before evolving the eccentricity of one model to the same reference frequency as the other model. We show that for a given value of eccentricity passed to SEOBNRE , one must input a 20%–50% smaller value of eccentricity to TEOBResumS in order to obtain a waveform with the same empirical eccentricity. We verify this mapping by repeating our analysis for eccentric numerical relativity simulations, demonstrating that TEOBResumS reports a correspondingly smaller value of eccentricity than SEOBNRE .
Publisher: American Astronomical Society
Date: 09-06-2011
Publisher: IOP Publishing
Date: 10-2009
Publisher: Oxford University Press (OUP)
Date: 20-05-2014
DOI: 10.1093/MNRAS/STU720
Publisher: Oxford University Press (OUP)
Date: 15-02-2016
DOI: 10.1093/MNRAS/STW347
Publisher: Oxford University Press (OUP)
Date: 19-02-2016
DOI: 10.1093/MNRAS/STW395
Publisher: American Physical Society (APS)
Date: 07-03-2013
Publisher: Cambridge University Press (CUP)
Date: 2023
DOI: 10.1017/PASA.2023.49
Publisher: American Physical Society (APS)
Date: 13-10-2009
Publisher: American Astronomical Society
Date: 18-12-2017
Publisher: American Physical Society (APS)
Date: 18-11-2008
Publisher: Springer Science and Business Media LLC
Date: 16-10-2017
DOI: 10.1038/NATURE24471
Abstract: On 17 August 2017, the Advanced LIGO and Virgo detectors observed the gravitational-wave event GW170817-a strong signal from the merger of a binary neutron-star system. Less than two seconds after the merger, a γ-ray burst (GRB 170817A) was detected within a region of the sky consistent with the LIGO-Virgo-derived location of the gravitational-wave source. This sky region was subsequently observed by optical astronomy facilities, resulting in the identification of an optical transient signal within about ten arcseconds of the galaxy NGC 4993. This detection of GW170817 in both gravitational waves and electromagnetic waves represents the first 'multi-messenger' astronomical observation. Such observations enable GW170817 to be used as a 'standard siren' (meaning that the absolute distance to the source can be determined directly from the gravitational-wave measurements) to measure the Hubble constant. This quantity represents the local expansion rate of the Universe, sets the overall scale of the Universe and is of fundamental importance to cosmology. Here we report a measurement of the Hubble constant that combines the distance to the source inferred purely from the gravitational-wave signal with the recession velocity inferred from measurements of the redshift using the electromagnetic data. In contrast to previous measurements, ours does not require the use of a cosmic 'distance ladder': the gravitational-wave analysis can be used to estimate the luminosity distance out to cosmological scales directly, without the use of intermediate astronomical distance measurements. We determine the Hubble constant to be about 70 kilometres per second per megaparsec. This value is consistent with existing measurements, while being completely independent of them. Additional standard siren measurements from future gravitational-wave sources will enable the Hubble constant to be constrained to high precision.
Publisher: American Astronomical Society
Date: 05-2023
Abstract: Gravitational waves from neutron star–black hole (NSBH) mergers that undergo tidal disruption provide a potential avenue to study the equation of state of neutron stars and hence the behavior of matter at its most extreme densities. We present a phenomenological model for the gravitational-wave signature of tidal disruption, which allows us to measure the disruption time. We carry out a study with mock data, assuming an optimistically nearby NSBH event with parameters tuned for measuring the tidal disruption. We show that a two-detector network of 40 km Cosmic Explorer instruments can measure the time of disruption with a precision of ≈0.5 ms, which corresponds to a constraint on the neutron star radius of ≈0.7 km (90% credibility). This radius constraint is wider than the constraint obtained by measuring the tidal deformability of the neutron star of the same system during the inspiral. Moreover, the neutron star radius is likely to be more tightly constrained using binary neutron star mergers. While NSBH mergers are important for the information they provide about stellar and binary astrophysics, they are unlikely to provide insights into nuclear physics beyond what we will already know from binary neutron star mergers.
Publisher: American Physical Society (APS)
Date: 20-08-2021
Publisher: American Astronomical Society
Date: 11-2021
Abstract: Orbital eccentricity is one of the most robust discriminators for distinguishing between dynamical and isolated formation scenarios of binary black hole mergers using gravitational-wave observatories such as LIGO and Virgo. Using state-of-the-art cluster models, we show how selection effects impact the detectable distribution of eccentric mergers from clusters. We show that the observation (or lack thereof) of eccentric binary black hole mergers can significantly constrain the fraction of detectable systems that originate from dynamical environments, such as dense star clusters. After roughly 150 observations, observing no eccentric binary signals would indicate that clusters cannot make up the majority of the merging binary black hole population in the local universe (95% credibility). However, if dense star clusters dominate the rate of eccentric mergers and a single system is confirmed to be measurably eccentric in the first and second gravitational-wave transient catalogs, clusters must account for at least 14% of detectable binary black hole mergers. The constraints on the fraction of detectable systems from dense star clusters become significantly tighter as the number of eccentric observations grows and will be constrained to within 0.5 dex once 10 eccentric binary black holes are observed.
Publisher: American Astronomical Society
Date: 16-10-2017
Publisher: American Association for the Advancement of Science (AAAS)
Date: 25-09-2015
Abstract: Gravitational waves are expected to be generated by the interaction of the massive bodies in black-hole binary systems. As gravitational waves distort spacetime, it should be possible to verify their existence as they interfere with the pulses emitted by millisecond pulsars. However, after monitoring 24 pulsars with the Parkes radio telescope for 12 years, Shannon et al. found no detectable variation in pulsar records. This nondetection result indicates that a new detection strategy for gravitational waves is needed. Science , this issue p. 1522
Publisher: IOP Publishing
Date: 06-2012
Publisher: American Physical Society (APS)
Date: 14-05-2007
Publisher: American Astronomical Society
Date: 22-05-2015
Publisher: Oxford University Press (OUP)
Date: 24-02-2016
DOI: 10.1093/MNRAS/STW435
Publisher: Cambridge University Press (CUP)
Date: 2015
DOI: 10.1017/PASA.2015.35
Abstract: Neutron stars are excellent emitters of gravitational waves. Squeezing matter beyond nuclear densities invites exotic physical processes, many of which violently transfer large amounts of mass at relativistic velocities, disrupting spacetime and generating copious quantities of gravitational radiation. I review mechanisms for generating gravitational waves with neutron stars. This includes gravitational waves from radio and millisecond pulsars, magnetars, accreting systems, and newly born neutron stars, with mechanisms including magnetic and thermoelastic deformations, various stellar oscillation modes, and core superfluid turbulence. I also focus on what physics can be learnt from a gravitational wave detection, and where additional research is required to fully understand the dominant physical processes at play.
Publisher: Oxford University Press (OUP)
Date: 30-10-2014
Publisher: American Astronomical Society
Date: 12-2022
Abstract: The growing population of compact binary mergers detected with gravitational waves contains multiple events that are challenging to explain through isolated binary evolution. Such events have higher masses than are expected in isolated binaries, component spin tilt angles that are misaligned, and/or nonnegligible orbital eccentricities. We investigate the orbital eccentricities of 62 binary black hole candidates from the third gravitational-wave transient catalog of the LIGO–Virgo–KAGRA Collaboration with an aligned-spin, moderate-eccentricity waveform model. Within this framework, we find that at least four of these events show significant support for eccentricity e 10 ≥ 0.1 at a gravitational-wave frequency of 10 Hz ( % credibility, under a log-uniform eccentricity prior that spans the range 10 −4 e 10 0.2). Two of these events are new additions to the population: GW191109 and GW200208_22. If the four eccentric candidates are truly eccentric, our results suggest that densely populated star clusters may produce 100% of the observed mergers. However, it remains likely that other formation environments with higher yields of eccentric mergers—for ex le, active galactic nuclei—also contribute. We estimate that we will be able to confidently distinguish which formation channel dominates the eccentric merger rate after ≳80 detections of events with e 10 ≥ 0.05 at LIGO–Virgo sensitivity, with only ∼5 detectably eccentric events required to distinguish formation channels with third-generation gravitational-wave detectors.
Publisher: American Physical Society (APS)
Date: 18-01-2012
Publisher: Oxford University Press (OUP)
Date: 28-04-2015
DOI: 10.1093/MNRAS/STV638
Publisher: American Physical Society (APS)
Date: 15-08-2018
Publisher: Cambridge University Press (CUP)
Date: 11-04-2022
DOI: 10.1017/ASB.2022.7
Abstract: While the current pandemic is causing mortality shocks globally, the management of longevity risk remains a major challenge for both in iduals and institutions. It is high time there be private market solutions designed for efficient longevity risk transfer among various stakeholders such as in iduals, pension funds and annuity providers. From in iduals’ point of view, appealing features of post-retirement solutions include stable and satisfactory benefit levels, flexibility, meeting bequest preferences and low fees. This paper proposes a dynamic target volatility strategy for group self-annuitization (GSA) schemes aimed at enhancing living benefits for pool participants. More specifically, we suggest investing GSA funds in a portfolio consisting of equity and cash, continuously rebalanced to maintain a target volatility level. The performance of a dynamic target volatility strategy is assessed against the static case which does not involve portfolio rebalancing. Benefit profiles are assessed by analysing quantiles and alternative strategies involving varying equity compositions. The case of death benefits is included, and the fund dynamics analysed by assessing resulting investment returns and the mortality credits. Overall, higher living benefit profiles are obtained under a dynamic target volatility strategy. From the analysis performed, a trade-off between the equity proportion and the impact on the lower quantile of the living benefit amount emerges, suggesting an optimal proportion of equity composition.
Publisher: American Astronomical Society
Date: 18-09-2018
Publisher: American Physical Society (APS)
Date: 07-07-2020
Publisher: American Physical Society (APS)
Date: 30-12-2010
Publisher: Cambridge University Press (CUP)
Date: 2015
DOI: 10.1017/PASA.2015.49
Abstract: The first observations by a worldwide network of advanced interferometric gravitational wave detectors offer a unique opportunity for the astronomical community. At design sensitivity, these facilities will be able to detect coalescing binary neutron stars to distances approaching 400 Mpc, and neutron star–black hole systems to 1 Gpc. Both of these sources are associated with gamma-ray bursts which are known to emit across the entire electromagnetic spectrum. Gravitational wave detections provide the opportunity for ‘multi-messenger’ observations, combining gravitational wave with electromagnetic, cosmic ray, or neutrino observations. This review provides an overview of how Australian astronomical facilities and collaborations with the gravitational wave community can contribute to this new era of discovery, via contemporaneous follow-up observations from the radio to the optical and high energy. We discuss some of the frontier discoveries that will be made possible when this new window to the Universe is opened.
Publisher: American Physical Society (APS)
Date: 12-11-2021
Publisher: Oxford University Press (OUP)
Date: 18-11-2015
Publisher: EDP Sciences
Date: 2008
DOI: 10.1051/EAS:0830028
Publisher: American Astronomical Society
Date: 14-02-2019
Publisher: IOP Publishing
Date: 15-01-2010
Publisher: Oxford University Press (OUP)
Date: 06-05-2015
DOI: 10.1093/MNRAS/STV726
Publisher: American Physical Society (APS)
Date: 26-02-2014
Publisher: American Physical Society (APS)
Date: 13-11-2020
Publisher: Cambridge University Press (CUP)
Date: 2022
DOI: 10.1017/PASA.2022.24
Abstract: Bayesian inference is a powerful tool in gravitational-wave astronomy. It enables us to deduce the properties of merging compact-object binaries and to determine how these mergers are distributed as a population according to mass, spin, and redshift. As key results are increasingly derived using Bayesian inference, there is increasing scrutiny on Bayesian methods. In this review, we discuss the phenomenon of model misspecification , in which results obtained with Bayesian inference are misleading because of deficiencies in the assumed model(s). Such deficiencies can impede our inferences of the true parameters describing physical systems. They can also reduce our ability to distinguish the ‘best fitting’ model: it can be misleading to say that Model A is preferred over Model B if both models are manifestly poor descriptions of reality. Broadly speaking, there are two ways in which models fail. Firstly, models that fail to adequately describe the data (either the signal or the noise) have misspecified likelihoods. Secondly, population models—designed, for ex le, to describe the distribution of black hole masses—may fail to adequately describe the true population due to a misspecified prior. We recommend tests and checks that are useful for spotting misspecified models using ex les inspired by gravitational-wave astronomy. We include companion python notebooks to illustrate essential concepts.
Publisher: Cambridge University Press (CUP)
Date: 2022
DOI: 10.1017/PASA.2022.1
Abstract: Proposed next-generation networks of gravitational-wave observatories include dedicated kilohertz instruments that target neutron star science, such as the proposed Neutron Star Extreme Matter Observatory, NEMO. The original proposal for NEMO highlighted the need for it to exist in a network of gravitational-wave observatories to ensure detection confidence and sky localisation of sources. We show that NEMO-like observatories have significant utility on their own as coincident electromagnetic observations can provide the detection significance and sky localisation. We show that, with a single NEMO-like detector and expected electromagnetic observatories in the late 2020 s and early 2030 s such as the Vera C. Rubin observatory and SVOM, approximately 40% of all binary neutron star mergers detected with gravitational waves could be confidently identified as coincident multimessenger detections. We show that we expect $2^{+10}_{-1}{yr^{-1}}{}$ coincident observations of gravitational-wave mergers with gamma-ray burst prompt emission, $13^{+23}_{-10}{yr^{-1}}{}$ detections with kilonova observations, and $4^{+18}_{-3}{yr^{-1}}{}$ with broadband afterglows and kilonovae, where the uncertainties are 90% confidence intervals arising from uncertainty in current merger-rate estimates. Combined, this implies a coincident detection rate of $14^{+25}_{-11}{yr^{-1}}{}$ out to $300\\,\\mathrm{Mpc}$ . These numbers indicate significant science potential for a single kilohertz gravitational-wave detector operating without a global network of other gravitational-wave observatories.
Publisher: American Astronomical Society
Date: 25-08-2022
Abstract: Analyses of quasi-periodic oscillations (QPOs) are important to understanding the dynamic behavior in many astrophysical objects during transient events like gamma-ray bursts, solar flares, magnetar flares, and fast radio bursts. Astrophysicists often search for QPOs with frequency-domain methods such as (Lomb–Scargle) periodograms, which generally assume power-law models plus some excess around the QPO frequency. Time-series data can alternatively be investigated directly in the time domain using Gaussian process (GP) regression. While GP regression is computationally expensive in the general case, the properties of astrophysical data and models allow fast likelihood strategies. Heteroscedasticity and nonstationarity in data have been shown to cause bias in periodogram-based analyses. GPs can take account of these properties. Using GPs, we model QPOs as a stochastic process on top of a deterministic flare shape. Using Bayesian inference, we demonstrate how to infer GP hyperparameters and assign them physical meaning, such as the QPO frequency. We also perform model selection between QPOs and alternative models such as red noise and show that this can be used to reliably find QPOs. This method is easily applicable to a variety of different astrophysical data sets. We demonstrate the use of this method on a range of short transients: a gamma-ray burst, a magnetar flare, a magnetar giant flare, and simulated solar flare data.
Publisher: American Physical Society (APS)
Date: 31-10-2018
Publisher: American Physical Society (APS)
Date: 17-03-2017
Publisher: IOP Publishing
Date: 02-2011
Publisher: Oxford University Press (OUP)
Date: 11-07-2009
Publisher: American Astronomical Society
Date: 06-2023
Abstract: There are at present ( 100 ) gravitational-wave candidates from compact binary mergers reported in the astronomical literature. As detector sensitivities are improved, the catalog will swell in size: first to ( 1000 ) events in the A+ era and then to ( 10 6 ) events in the era of third-generation observatories like Cosmic Explorer and the Einstein Telescope. Each event is analyzed using Bayesian inference to determine properties of the source including component masses, spins, tidal parameters, and the distance to the source. These inference products are the fodder for some of the most exciting gravitational-wave science, enabling us to measure the expansion of the universe with standard sirens, to characterize the neutron-star equation of state, and to unveil how and where gravitational-wave sources are assembled. In order to maximize the science from the coming deluge of detections, we introduce GW Cloud , a searchable repository for the creation and curation of gravitational-wave inference products. It is designed with five pillars in mind: uniformity of results, reproducibility of results, stability of results, access to the astronomical community, and efficient use of computing resources. We describe how to use GW Cloud with ex les, which readers can replicate using the companion code to this paper. We describe our long-term vision for GW Cloud .
Publisher: Oxford University Press (OUP)
Date: 12-2015
Publisher: American Physical Society (APS)
Date: 18-12-2020
Publisher: American Astronomical Society
Date: 22-08-2016
Publisher: American Physical Society (APS)
Date: 31-03-2016
Publisher: American Physical Society (APS)
Date: 10-07-2015
Start Date: 05-2018
End Date: 08-2021
Amount: $238,048.00
Funder: Australian Research Council
View Funded ActivityStart Date: 06-2017
End Date: 11-2021
Amount: $652,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 09-2021
End Date: 08-2025
Amount: $3,000,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 04-2017
End Date: 03-2024
Amount: $31,300,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2023
End Date: 12-2026
Amount: $460,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2022
End Date: 06-2025
Amount: $450,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 02-2022
End Date: 12-2023
Amount: $672,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 04-2024
End Date: 03-2031
Amount: $35,000,000.00
Funder: Australian Research Council
View Funded Activity