Decoding Continuous Gravitational Waves from Pulsars: A Multi-Wavelength Approach
type: CreativeWork
description: The detection of continuous gravitational wave (CW) signals from isolated neutron stars will provide new insights into the physics of neutron stars and significantly contribute to the field of gravitational wave (GW) astronomy. CW signals are expected, for instance, from young pulsars with non-axisymmetric configurations, particularly those within pulsar wind nebulae (PWNe). However, detecting such signals poses significant challenges, requiring advanced data analysis techniques and the integration of multi-wavelength observations. The research presented in this thesis focuses on developing, applying, and refining methodologies to detect CW signals using data from ground-based GW detectors and Imaging Atmospheric Cherenkov Telescopes (IACTs). In particular, this research integrates very-high-energy (VHE) observations from the High Energy Stereoscopic System (HESS) with data from the second observing run of the Advanced Laser Interferometer Gravitational-Wave Observatory (aLIGO) to enhance the sensitivity of CW detection strategies. The initial chapters review the evolution of CW search techniques, emphasising the critical role of IACTs in addressing challenges in CW signal detection. Young pulsars within PWNe are highlighted as prime candidates for CW searches due to the non-axisymmetric configurations expected shortly after formation. A novel search framework is introduced and applied in two CW searches, as detailed in our peer-reviewed publications. In both cases, we employ a semi-coherent analysis method that combines the F-statistic with a hidden Markov model (HMM) to track the stochastic wandering of the CW signal frequency throughout the observation period. This approach strikes a good balance between computational efficiency and sensitivity. The first search targets ten pulsars associated with TeV-bright sources, refining the CW search parameter space by using the TeV properties of these sources. A semi-coherent targeted search reveals 5,256 candidates across…
abstract: The detection of continuous gravitational wave (CW) signals from isolated neutron stars will provide new insights into the physics of neutron stars and significantly contribute to the field of gravitational wave (GW) astronomy. CW signals are expected, for instance, from young pulsars with non-axisymmetric configurations, particularly those within pulsar wind nebulae (PWNe). However, detecting such signals poses significant challenges, requiring advanced data analysis techniques and the integration of multi-wavelength observations. The research presented in this thesis focuses on developing, applying, and refining methodologies to detect CW signals using data from ground-based GW detectors and Imaging Atmospheric Cherenkov Telescopes (IACTs). In particular, this research integrates very-high-energy (VHE) observations from the High Energy Stereoscopic System (HESS) with data from the second observing run of the Advanced Laser Interferometer Gravitational-Wave Observatory (aLIGO) to enhance the sensitivity of CW detection strategies. The initial chapters review the evolution of CW search techniques, emphasising the critical role of IACTs in addressing challenges in CW signal detection. Young pulsars within PWNe are highlighted as prime candidates for CW searches due to the non-axisymmetric configurations expected shortly after formation. A novel search framework is introduced and applied in two CW searches, as detailed in our peer-reviewed publications. In both cases, we employ a semi-coherent analysis method that combines the F-statistic with a hidden Markov model (HMM) to track the stochastic wandering of the CW signal frequency throughout the observation period. This approach strikes a good balance between computational efficiency and sensitivity. The first search targets ten pulsars associated with TeV-bright sources, refining the CW search parameter space by using the TeV properties of these sources. A semi-coherent targeted search reveals 5,256 candidates across…
author: Beniwal, Deeksha
language: en
keywords: Continuous gravitational-wave detection, data analysis, targeted searches, directed searches, HESS
date published: 2025
date modified: 2026-07-24T00:51:10Z
provider: University of Adelaide
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Adelaide

PropertyValue
property ID: Handle
value: https://hdl.handle.net/2440/144773