Searching for gravitational waves from precessing binaries

The first detection of precessing Binary Black Holes (BBH) will open up new perspectives in gravitational waves (GW) astronomy, providing, among other advancements, a precise measure of distance and an accurate characterization of the BBH spins.

However, detecting precessing signals poses a highly non-trivial challenge, as standard matched filtering pipelines for GW searches rely on several assumptions that do not hold in the precessing case.

We describe the new search statistics and the new signal consistency test implemented in the GstLAL pipeline to facilitate the search for precessing binary black hole (BBH) signals.

The benefits of the upgrades are assessed by comparing the sensitive volume of a precessing search against two corresponding ``standard" aligned spin searches. While no significant sensitivity improvement is observed for mildly precessing signals, a volume increase of up to 100% is attainable for heavily precessing asymmetric systems with large misaligned spins.

Finally, we discuss some preliminary results from a large scale search on the publicly available O3 interferometer data, targeting heavily precessing systems that have never been detected before.