Exploring the Universe with Gravitational Wave Observations from LIGO, Virgo, and KAGRA

The past 10 years of gravitational wave observations with the Laser Interferometer Gravitational-wave Observatory (LIGO) have resulted in the first detection of gravitational waves, the first observation 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. We are now concluding the fourth observing run and preparing for the second decade of gravitational wave observations. Together with the European Virgo detector and the Japanese KAGRA detector, this international gravitational-wave detector network will transition to near-continuous operation with unsurpassed sensitivity. 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. The project 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. It will train a new generation of graduate students and postdoctoral fellows in gravitational-wave astronomy and prepare them for new horizons in this still young field. 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 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 an online search for signals from compact binary coalescence and a near real-time source parameter estimation and classification system. 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. To this end, this project supports work 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.