Programme

P.58 -- Posters, VCTP-50

Date: Thursday, 7 August 2025

Time: 08:30 - 10:00

Modeling Gravitational Wave Signatures from Magnetars Using Generally-Relativistic Magnetohydrodynamic Simulations

Nguyen Thi Thao Trang (1), Lott Peter Tell (1), Nguyen Quynh Lan (1)

(1) Phenikaa University

Magnetars, highly magnetized neutron stars, generate gravitational waves through asymmetries in their crust and magnetic field, often referred to as "mountains". These deformations arise from strong magnetic stresses and rotational forces, leading to a time-varying mass quadrupole moment that produces gravitational wave emission within the detectability band of current ground-based detectors. We employ Athena++, a general relativistic magnetohydrodynamic framework, to simulate a physically realistic magnetar, initializing a strong dipolar magnetic field and introducing a localized deformation in the crust. The simulation evolves under fully relativistic conditions, capturing the coupled effects of magnetic stress, rotational forces, and hydrodynamic feedback. We extract gravitational waveforms using the quadrupole approximation and analyze through Fourier transforms to uncover dominant frequency components and their temporal evolution. A parameter study across magnetic field strengths, deformation scales, and rotation rates reveals the optimal conditions for generating detectable gravitational wave signals. When compared against the sensitivity curves of ground-based gravitational-wave detectors, the results suggest that certain magnetar configurations may produce marginally detectable signals. This work may be relevant for search for long-term signals from mountains on magnetars.

Presenter: Nguyen Thi Thao Trang