Search for gravitational waves associated with the gamma ray burst GRB030329 using the LIGO detectors

We have performed a search for bursts of gravitational waves associated with the very bright gamma ray burst GRB030329, using the two detectors at the LIGO Hanford Observatory. Our search covered the most sensitive frequency range of the LIGO detectors (approximately $80–-2048\mathrm{Hz}$), and we specifically targeted signals shorter than $\simeq 150\mathrm{ms}$. Our search algorithm looks for excess correlated power between the two interferometers and thus makes minimal assumptions about the gravitational waveform. We observed no candidates with gravitational-wave signal strength larger than a predetermined threshold. We report frequency-dependent upper limits on the strength of the gravitational waves associated with GRB030329. Near the most sensitive frequency region, around $\simeq 250\mathrm{Hz}$, our root-sum-square (RSS) gravitational-wave strain sensitivity for optimally polarized bursts was better than $h_{\mathrm{RSS}}\simeq 6\times {10}^{-21}{\mathrm{Hz}}^{-1/2}$. Our result is comparable to the best published results searching for association between gravitational waves and gamma ray bursts.