Searches for Gravitational Wave Transients: Data Analysis for Advanced LIGO

Gravitational waves are the ripples in the fabric of space-time created by moving masses, which travel through the universe at the speed of light. Predicted by Albert Einstein's 1915 theory of General Relativity, gravitational waves eluded detection for a hundred years, until on September 14, 2015, shortly after the major upgrade, the advanced LIGO detectors observed a gravitational wave signal from two colliding black holes. For the first time, LIGO detected ripples in the fabric of space-time arriving at the Earth from a cataclysmic event in the distant universe. This confirmed a major prediction of General Relativity and opened an unprecedented new window onto the cosmos. Gravitational-waves provide a direct probe of complex astrophysical systems and provide a unique astronomical tool to study the Universe. In the next few years hundreds detections of sources are expected as advanced LIGO reaches its design sensitivity and the other instruments join the world-wide network of gravitational wave detectors. The experiments with these detectors will address key research questions, including the formation and evolution of black holes and neutron stars, the role of compact objects in high energy emission, the properties of nuclear matter, the nature of gamma-ray-bursts, and the existence of intermediate-mass black holes, probing the structure and evolution of the Universe and physics beyond General Relativity.

The proposed research will reinforce success of the LIGO data analysis effort and support new innovative research projects that have a potential to produce transformative results. It targets the most extreme astrophysical events, such as recently discovered mergers of neutron stars and black holes, and holds a promise for discoveries of entirely new astrophysical phenomena. The proposed searches utilize the detection and reconstruction algorithms that use minimal model assumptions and that are capable of detecting gravitational-wave transients in a wide range of source parameters, including yet unknown sources. Among the primary detection targets is a core collapse supernovae (CCSN), which will address a number of open questions in astrophysics, such as the role of neutrino in CCSN and the neutron star equations of state. Also, the proposed activities will extend the most promising advanced LIGO searches for compact binary sources into the binary parameter space not yet explored by the existing template algorithms. The proposed searches have a potential to establish the existence of intermediate mass binary black holes and test the theory of general relativity at the high field regime by comparing the reconstructed signal waveforms with the numerical relativity predictions. Novel methods are proposed for studies of the compact binary post-merger signals, including quasi-normal gravitational waves emitted by the remnant black holes and post-merger signatures of the binary neutron star systems. Rapid source reconstruction and sky localization will enable joint observations with the electromagnetic telescopes and neutrino detectors, advancing the field of the multi-messenger astronomy. This award will also support the planned upgrade of the baseline LIGO data analysis algorithms for the future LIGO runs and increase the scientific potential of the proposed gravitational-wave observations.

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.