Gravitational-Wave Astronomy with the LIGO-Virgo-KAGRA Network

This award supports research in relativity and relativistic astrophysics, and it addresses the priority areas of NSF's "Windows on the Universe" Big Idea. The three observing runs of the Laser Interferometer Gravitational-wave Observatory (LIGO) have provided multiple firsts: the first observation of gravitational waves, of binary black holes, and of black-hole neutron-star binaries, as well as the beginning of the era of multimessenger astronomy with gravitational waves.

The fourth observing run of the Advanced LIGO detectors will soon take place. In coordination with the European Virgo detector and the Japanese KAGRA detector, this network of gravitational-wave observatories will survey the universe with unprecedented sensitivity. A trove of new discoveries is at hand.

This project supports the research activities of the University of Wisconsin–Milwaukee (UWM) LIGO Scientific Collaboration (LSC) group. The overarching theme is gravitational-wave astronomy with an emphasis on activities that are on the critical path for the scientific success of LIGO and its full participation in multimessenger transient astronomy.

This project brings highly-engaged faculty with a proven track record in gravitational physics, astrophysics, data analysis, education and outreach together with undergraduates, graduate students and postdocs in a close collaborative environment to deliver science at the dawn of multimessenger gravitational-wave astronomy. It supports the creation of critical components of a system that will allow the rapid transmittal of gravitational-wave observations to the entire community of astronomers and facilitates the integration of gravitational-wave science into the broader field of astrophysics.

The excitement of gravitational-wave astronomy will be communicated to the community through programs at the UWM Planetarium and the student-led Coffeeshop Astrophysics.

The UWM LSC group will deliver several critical elements to a low-latency, streaming search for transient gravitational waves including those produced during the coalescence of binary neutron stars and/or black holes. Among the data analysis elements the group will help develop and operate are the online search for signals from compact binary coalescence, a near real-time source classification system, and a rapid parameter estimation utility.

A system to rapidly identify signals is an essential element of gravitational-wave science in the era of multimessenger astronomy in which observations of several kinds (gravitational waves; electromagnetic waves; high energy particles) are synthesized to obtain a detailed understanding of the sources of the most cataclysmic events in the universe. Gravitational-wave astronomy offers a new window into the realm of transient astronomy that complements other astronomical facilities, provides a means to measure the population of black holes and determine the channel by which massive black holes are grown, and enables us to probe the fundamental nature of matter above nuclear densities.

We must be ready to handle the increasing rate of detections in order to address these scientific challenges. To this end, this project supports work, identified as critical path in the LIGO/Virgo/KAGRA Observational Science and Operations White Papers and the LSC Program, that will result in gravitational-wave detections of binary coalescence, provide rapid sky localization and parameter estimation to facilitate electromagnetic follow-up efforts, yield fast turn-around targeted searches prompted by triggers generated by other observational facilities, give insight into the population of coalescing compact binaries, and obtain the nuclear equation of state by measuring the tidal interactions of binary neutron stars.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.