The LIGO Team
at The University of Mississippi
The new Advanced Laser Interferometer Gravitational-wave (aLIGO) detectors performed their first observing run from September 2015 to January 2016. This event marked a momentous time in the decades-old search for gravitational waves. Almost one hundred years after Albert Einstein's theoretical proof of the existence of gravitational waves, the new aLIGO instruments offer scientists a concrete chance of directly detecting these ''ripples in space-time'' for the first time. Current rate estimates of astrophysical events indicate that aLIGO and her sister advanced detectors will likely detect gravitational waves within a few years from their onset, perhaps recording the final death spiral of two orbiting black holes hundreds of million light year away. Detection and measurement of these signals will open an exciting new window on the universe, heralding the arrival of gravitational-wave astronomy as a revolutionary, new observational field. As so often happens when scientists enter a new domain of observation and measurement, aLIGO may even surprise us with totally unexpected discoveries.
|aLIGO performs searches for gravitational waves of various astrophysical origin. Different methods of signal extraction are used according to the nature of the search. For example, searches for the cosmic stochastic background of gravitational waves rely on cross-correlation methods, while searches for coalescence of compact binary objects make use of matched filtering techniques with template banks that include hundreds of gravitational-wave waveforms from compact binary systems of neutron stars and black holes. In all these searches, characterization of the aLIGO detectors and their data quality is critical. The aLIGO detectors are sensitive to a variety of disturbances of non-astrophysical origin with characteristic frequencies in the instrument band of sensitivity. Noise transients of instrumental or environmental origin increase the false alarm rate of the searches by generating fake triggers in data streams. A successful reduction of non-astrophysical noise increases the instrument duty cycles and improve chances of signal detection. For all of these reasons, Detector Characterization (DetChar), i.e., the understanding of non-astrophysical disturbances and their mitigation, is one of the top priorities of aLIGO scientists.|
The University of Mississippi joined the LIGO Scientific Collaboration (LSC) in July 2007. In the years since the inception of the UM-LIGO group, Mississippi's researchers and students have received continuous NSF support to sustain LIGO's core mission through contributions in detector characterization, data analysis, service, and education and public outreach. The current focus of the UM-LIGO group is in commissioning, detector characterization and detector development, in particular:
- Commissioning. UM-LIGO researchers work with LSC colleagues at the Observatories to improve the performance of the detectors. These tasks are carried out on site by some of the UM-LIGO members residing for extended periods of time in Livingston and Hanford.
- Detector characterization. UM-LIGO researchers work in close contact with aLIGO instrumentalists, data analysts and the LSC DetChar group to monitor and improve the performance of the detectors, and mitigate unwanted non-astrophysical features in the data in order to reduce the background of aLIGO's astrophysical searches. These tasks are carried out by developing new data analysis and Detchar tools, as well as through the use of existing LIGO DetChar tools and data mining techniques.
- Third-generation detector development. UM-LIGO researchers are developing instrumentation and experimental techniques to improve the interferometers' sensitivity to gravitational waves. We are building quantum optics experiments to manipulate Heisenberg's Uncertainty Principle and we are prototyping a tilt-free seismometer to filter out the unwanted effects of Einstein's Equivalence Principle. Together, both lines of research will ultimately improve the interferometers' sensitivity to binary black holes, contribute to putting limits on the elusive neutron star equation of state, and increase the duty cycle of the detectors.