Einstein@Home all-sky "bucket" search for continuous gravitational waves in LIGO O3 public data

Continuous gravitational waves are nearly monochromatic, long-lasting signals that are expected to be produced by rapidly rotating non-axisymmetric neutron stars and may also come from more exotic sources such as the inspiral of dark-matter objects or superradiant emission of axion-like particles around black holes.

   

Despite numerous detections of gravitational waves from compact binary coalescences, continuous gravitational waves have yet to be detected. One approach to search for continuous gravitational waves is through broad parameter range searches, where the waveform parameters of the signal and the source location are unknown. These types of searches are among the most computationally intensive, often requiring months of processing on large supercomputer clusters.

  

We present our latest broad parameter range search results for continuous gravitational waves in LIGO O3 public data, over the most sensitive frequency band "bucket" of the Hanford and Livingston detectors. This is the most sensitive all-sky search performed to date. We highlight the most constraining frequentist upper limits on the detectable intrinsic continuous wave amplitude and source ellipticity.

   

 A successful detection of continuous gravitational waves could reveal the extreme physical properties of neutron star matter and improve our understanding of the galactic population of electromagnetically invisible compact objects.