Fluid accretion onto relativistic stars and gravitational radiation

TL;DR

This paper presents numerical simulations of gravitational waves emitted by nonrotating relativistic stars during axisymmetric fluid accretion, using a hybrid approach combining perturbation theory and hydrodynamics.

Contribution

It introduces a hybrid numerical method to simulate gravitational radiation from accreting relativistic stars, neglecting self-gravity and radiation reaction effects.

Findings

Simulated gravitational wave signals from accreting stars.

Characterized the waveform features related to accretion dynamics.

Provided insights into gravitational radiation emission mechanisms.

Abstract

This article reports results from numerical simulations of the gravitational radiation emitted from nonrotating relativistic stars as a result of the axisymmetric accretion of layers of perfect fluid matter, shaped in the form of quadrupolar shells. We adopt a {\em hybrid} procedure where we evolve numerically the polar nonspherical perturbations equations of the star coupled to a fully nonlinear hydrodynamics code that calculates the motion of the accreting matter. Self-gravity of the accreting fluid as well as radiation reaction effects are neglected.