The detection of gravitational waves (GWs) from binary neutron stars (BNSs) with possible telescope follow-ups opens a window to ground-breaking discoveries in the field of multi-messenger astronomy. With the improved sensitivity of current and future GW detectors, more BNS detections are expected in the future. Therefore, enhancing low-latency GW search algorithms to achieve rapid speed, high accuracy, and low computational cost is essential. One innovative solution to reduce latency is the use of machine learning (ML) methods embedded in field-programmable gate arrays (FPGAs). In this work, we present a novel WaveNet-based method, leveraging the state-of-the-art ML model, to produce early-warning alerts for BNS systems. Using simulated GW signals embedded in Gaussian noise from the Advanced LIGO and Advanced Virgo detectors’ third observing run (O3) as a proof-of-concept dataset, we demonstrate significant performance improvements. Compared to the current leading ML-based early-warning system, our approach enhances detection accuracy from 66.81% to 76.22% at a 1% false alarm probability. Furthermore, we evaluate the time, energy, and economical cost of our model across CPU, GPU, and FPGA platforms, showcasing its potential for deployment in real-time gravitational wave detection pipelines.
This content will become publicly available on May 23, 2025
The ground-based gravitational wave (GW) detectors LIGO and Virgo have enabled the birth of multi-messenger GW astronomy via the detection of GWs from merging stellar-mass black holes (BHs) and neutron stars (NSs). GW170817, the first binary NS merger detected in GWs and all bands of the electromagnetic spectrum, is an outstanding example of the impact that GW discoveries can have on multi-messenger astronomy. Yet, GW170817 is only one of the many and varied multi-messenger sources that can be unveiled using ground-based GW detectors. In this contribution, we summarize key open questions in the astrophysics of stellar-mass BHs and NSs that can be answered using current and future-generation ground-based GW detectors, and highlight the potential for new multi-messenger discoveries ahead.
more » « less- PAR ID:
- 10510800
- Publisher / Repository:
- https://www.frontiersin.org
- Date Published:
- Journal Name:
- Frontiers in Astronomy and Space Sciences
- Volume:
- 11
- ISSN:
- 2296-987X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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ABSTRACT Rotating neutron stars (NSs) are promising sources of gravitational waves (GWs) in the frequency band of ground-based detectors. They are expected to emit quasi-monochromatic, long-duration GW signals, called continuous waves (CWs), due to their deviations from spherical symmetry. The degree of such deformations, and hence the information about the internal structure of an NS, is encoded in a dimension-less parameter ε called ellipticity. Searches for CW signals from isolated Galactic NSs have shown to be sensitive to ellipticities as low as $\varepsilon \sim \mathcal {O}(10^{-9})$. These searches are optimal for detecting and characterizing GWs from individual NSs, but they are not designed to measure the properties of NSs as population, such as the average ellipticity εav. These ensemble properties can be determined by the measurement of the stochastic gravitational-wave background (SGWB) arising from the superposition of GW signals from individually undetectable NSs. In this work, we perform a cross-correlation search for such a SGWB using the data from the first three observation runs of Advanced LIGO and Virgo. Finding no evidence for an SGWB signal, we set upper limits on the dimension-less energy density parameter Ωgw(f). Using these results, we also constrain the average ellipticity of Galactic NSs and five NS ‘hotspots’, as a function of the number of NSs emitting GWs within the frequency band of the search Nband. We find $\varepsilon _{\mathrm{av}} \lesssim 1.8 \times 10^{-8}$, with Nband = 1.6 × 107, for Galactic NSs, and $\varepsilon _{\mathrm{av}} \lesssim [3.5-11.8]\times 10^{-7}$, with Nband = 1.6 × 1010, for NS hotspots.
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Abstract Intermediate-mass black holes (IMBHs) are believed to be the missing link between the supermassive black holes (BHs) found at the centers of massive galaxies and BHs formed through stellar core collapse. One of the proposed mechanisms for their formation is a collisional runaway process in high-density young star clusters, where an unusually massive object forms through repeated stellar collisions and mergers, eventually collapsing to form an IMBH. This seed IMBH could then grow further through binary mergers with other stellar-mass BHs. Here we investigate the gravitational-wave (GW) signals produced during these later IMBH–BH mergers. We use a state-of-the-art semi-analytic approach to study the stellar dynamics and to characterize the rates and properties of IMBH–BH mergers. We also study the prospects for detection of these mergers by current and future GW observatories, both space-based (LISA) and ground-based (LIGO Voyager, Einstein Telescope, and Cosmic Explorer). We find that most of the merger signals could be detected, with some of them being multiband sources. Therefore, GWs represent a unique tool to test the collisional runaway scenario and to constrain the population of dynamically assembled IMBHs.
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Abstract The observation of transient gravitational waves (GWs) is hindered by the presence of transient noise, colloquially referred to as glitches. These glitches can often be misidentified as GWs by searches for unmodeled transients using the excess-power type of methods and sometimes even excite template waveforms for compact binary coalescences while using matched filter techniques. They thus create a significant background in the searches. This background is more critical in getting identified promptly and efficiently within the context of real-time searches for GW transients. Such searches are the ones that have enabled multi-messenger astrophysics with the start of the Advanced LIGO and Advanced Virgo data taking in 2015 and they will continue to enable the field for further discoveries. With this work we propose and demonstrate the use of a signal-based test that quantifies the fidelity of the time-frequency decomposition of the putative signal based on first principles on how astrophysical transients are expected to be registered in the detectors and empirically measuring the instrumental noise. It is based on the Q-transform and a measure of the occupancy of the corresponding time-frequency pixels over select time-frequency volumes; we call it ‘QoQ’. Our method shows a 40% reduction in the number of retraction of public alerts that were issued by the LIGO-Virgo-KAGRA collaborations during the third observing run with negligible loss in sensitivity. Receiver Operator Characteristic measurements suggest the method can be used in online and offline searches for transients, reducing their background significantly.
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