ausblenden:
Schlagwörter:
Astrophysics, High Energy Astrophysical Phenomena, astro-ph.HE
Zusammenfassung:
In this paper we report on a search for short-duration gravitational wave
bursts in the frequency range 64 Hz-1792 Hz associated with gamma-ray bursts
(GRBs), using data from GEO600 and one of the LIGO or Virgo detectors. We
introduce the method of a linear search grid to analyse GRB events with large
sky localisation uncertainties such as the localisations provided by the Fermi
Gamma-ray Burst Monitor (GBM). Coherent searches for gravitational waves (GWs)
can be computationally intensive when the GRB sky position is not
well-localised, due to the corrections required for the difference in arrival
time between detectors. Using a linear search grid we are able to reduce the
computational cost of the analysis by a factor of O(10) for GBM events.
Furthermore, we demonstrate that our analysis pipeline can improve upon the sky
localisation of GRBs detected by the GBM, if a high-frequency GW signal is
observed in coincidence. We use the linear search grid method in a search for
GWs associated with 129 GRBs observed satellite-based gamma-ray experiments
between 2006 and 2011. The GRBs in our sample had not been previously analysed
for GW counterparts. A fraction of our GRB events are analysed using data from
GEO600 while the detector was using squeezed-light states to improve its
sensitivity; this is the first search for GWs using data from a squeezed-light
interferometric observatory. We find no evidence for GW signals, either with
any individual GRB in this sample or with the population as a whole. For each
GRB we place lower bounds on the distance to the progenitor, assuming a fixed
GW emission energy of $10^{-2} M_{\odot}c^{2}$, with a median exclusion
distance of 0.8 Mpc for emission at 500 Hz and 0.3 Mpc at 1 kHz. The reduced
computational cost associated with a linear search grid will enable rapid
searches for GWs associated with Fermi GBM events in the Advanced detector era.
