Very high frequency gravitational waves from magnetars and gamma-ray burst

TL;DR

This paper explores the potential for extremely high-frequency gravitational waves generated by magnetars and gamma-ray bursts, proposing their distinctive features and detectability in future observational efforts.

Contribution

It introduces the concept of Gamma-HFGWs produced by interactions of GRB radiation with magnetar magnetic fields, highlighting their unique signatures and potential as astrophysical GW sources.

Findings

Gamma-HFGWs could have energy densities around 10^{-6} in the far field.

Detected signals might be around 10^{-20}W/m^2 in planned systems.

Distinctive envelope shapes could help identify Gamma-HFGWs.

Abstract

Extremely powerful astrophysical electromagnetic (EM) system could be possible source of high-frequency gravitational waves (HFGWs). Here based on properties of magnetars and gamma-ray bursts (GRBs), we address "Gamma-HFGWs" (with very high-frequency around 10^{20}Hz) caused by ultra-strong EM radiations (in the radiation-dominated phase of GRBs fireball) interacting with super-high magnetar surface magnetic fields (around 10^{11}Tesla). By certain parameters of distance and power, the Gamma-HFGWs would have far field energy density around 10^{-6}, and they would cause perturbed signal EM waves of around 10^{-20}Watt/m^2 in planned HFGW detection system based on EM response to GWs. Specially, Gamma-HFGWs would possess distinctive envelopes with characteristic shapes depending on the particular structures of surface magnetic fields of magnetars, which could be exclusive features helpful to distinguish them from background noise. Results obtained suggest that magnetars could involve in possible astrophysical EM sources of GWs in very high-frequency band, and Gamma-HFGWs would be potential targets for observations in the future.