Searching for Continuous Gravitational Waves: Methods and Results

Metro Toronto Convention Centre 

Since the start of the first Advanced LIGO observing run in 2015, nearly 100 gravitational wave events have been observed using data from the LIGO and Virgo detectors. In addition to these short-lived transient signals, the LIGO-Virgo-KAGRA collaboration conducts searches for a variety of other signals, including weaker but long-lived continuous gravitational waves, mostly from rapidly spinning neutron stars. To search for these signals, which are nearly periodic, but Doppler-modulated by the motion of the Earth and the source, one must analyze long stretches of data. A variety of techniques are employed, depending on the amount of information (sky position, spin frequency and evolution, binary orbit) available about potential sources. I will describe these methods, which typically need to balance sensitivity, computing cost and robustness, and summarize the results through the first three observing runs of advanced gravitational wave detectors.