Searches for Gravitational Wave Transients: Data Analysis and Detector Characterization for Advanced LIGO

Gravitational waves are ripples in the curvature of space-time created by moving masses, which travel through the universe at the speed of light. Predicted by Einstein's Theory of General Relativity (GR) - the most commonly accepted model of gravity - gravitational waves have not been detected yet. The direct observations of gravitational waves would be one of the most fundamental results in the modern science and the ultimate test of GR. Also gravitational waves will be a radically new tool for exploring fundamental physics and astronomy. They will probe the physics driving the most violent astrophysical events in the universe in ways inaccessible to electromagnetic astronomy. The construction of the U.S. Advanced Laser Interferometer Gravitational-wave Observatory (aLIGO) is almost complete. The aLIGO detectors will conduct the first observations in the fall 2015. Within the next few years, aLIGO and its international partner detectors Virgo and Kagra expect to make the first detections of gravitational waves from merging compact binary objects, such as neutron stars and black holes. Gravitational waves produced by the collision of black holes, asymmetric core collapse supernovae, rapidly spinning neutron stars, and even by the Big Bang itself are targets for detection in the years to come.

This award supports high priority searches for gravitational-wave transients from a broad class of astrophysical sources. These searches are capable of detecting gravitational transients in a wide range of source parameters, including yet unknown sources. They target the most extreme astrophysical events, such as supernovae, gamma-ray-bursts, mergers of neutron stars and black holes, and hold a promise for discoveries of entirely new astrophysical phenomena. Also, they will extend the most promising advanced LIGO searches for compact binary sources into the binary parameter space not covered by the existing template algorithms. These searches have a potential to establish the existence of intermediate mass binary black holes, look inside the galactic nuclei by detecting binaries with the eccentric orbits, and test the theory of general relativity at high field regime with the intermediate mass ratio binary sources. Rapid source reconstruction and sky localization will enable joint observations, with the electromagnetic telescopes advancing the field of the multi-messenger astronomy. Sophisticated signal processing algorithms and source reconstruction methods will be implemented and applied to find the source polarization and waveforms. A novel wavelet regression method will be used for the analysis and characterization of aLIGO data, targeting identification, monitoring and cancellation of environmental noise coupled into the detector output. Studies of noise sources will be performed and novel noise cancellation techniques will be tested to enable the first confident detection of gravitational-wave transients.