Search for gravitational wave radiation associated with the pulsating tail of the SGR 1806−20 hyperflare of 27 December 2004 using LIGO

Authors

B. P. Abbott
R. AbbottFollow
Mario C. Diaz, The University of Texas Rio Grande ValleyFollow
R. Grosso, The University of Texas Rio Grande Valley
Soumya Mohanty, The University of Texas Rio Grande ValleyFollow
Soma Mukherjee, The University of Texas Rio Grande ValleyFollow
Cristina V. Torres, The University of Texas Rio Grande Valley

Document Type

Article

Publication Date

9-2007

Abstract

We have searched for gravitational waves (GWs) associated with the SGR 1806−20 hyperflare of 27 December 2004. This event, originating from a Galactic neutron star, displayed exceptional energetics. Recent investigations of the x-ray light curve’s pulsating tail revealed the presence of quasiperiodic oscillations (QPOs) in the 30–2000 Hz frequency range, most of which coincides with the bandwidth of the LIGO detectors. These QPOs, with well-characterized frequencies, can plausibly be attributed to seismic modes of the neutron star which could emit GWs. Our search targeted potential quasimonochromatic GWs lasting for tens of seconds and emitted at the QPO frequencies. We have observed no candidate signals above a predetermined threshold, and our lowest upper limit was set by the 92.5 Hz QPO observed in the interval from 150 s to 260 s after the start of the flare. This bound corresponds to a (90% confidence) root-sum-squared amplitude h90%rss−det=4.5×10−22  strain  Hz−1/2 on the GW waveform strength in the detectable polarization state reaching our Hanford (WA) 4 km detector. We illustrate the astrophysical significance of the result via an estimated characteristic energy in GW emission that we would expect to be able to detect. The above result corresponds to 7.7×1046  erg (=4.3×10−8  M⊙c2), which is of the same order as the total (isotropic) energy emitted in the electromagnetic spectrum. This result provides a means to probe the energy reservoir of the source with the best upper limit on the GW waveform strength published and represents the first broadband asteroseismology measurement using a GW detector.

Comments

© 2007 American Physical Society. Original published version available at https://doi.org/10.1103/PhysRevD.76.062003

Recommended Citation

Abbott, B., et al. “Search for Gravitational Wave Radiation Associated with the Pulsating Tail of the SGR 1806−20 Hyperflare of 27 December 2004 Using LIGO.” Physical Review D, vol. 76, no. 6, American Physical Society, Sept. 2007, p. 062003, doi:10.1103/PhysRevD.76.062003.

Publication Title

Physical Review D

DOI

10.1103/PhysRevD.76.062003