Research in Support of LIGO Binary Inspiral Search and Detector Characterization

Louisiana Tech University, Ruston LA

Investigators

Abstract

One of the objectives of the Laser Interferometer Gravitational-wave Observatory (LIGO) is to detect gravitational waves from exotic astrophysical sources including binary systems consisting of neutron stars and/or black holes. Such systems are expected, in terms of general relativity, to send out gravitational waves as they approach coalescence. The LIGO Scientific Collaboration's Inspiral Analysis Group has set upper limits for the rate of coalescence of such systems using data from LIGO's first two science runs, and hopes to be able to detect them in future runs. This award supports aspects of the work needed to fully analyze LIGO data. One of these is the study of glitch (i.e. instrumental noise spike) propagation through the LIGO interferometer, the couplings between different channels of the LIGO instrument, and finding the channels where environmental glitches or glitches in auxiliary interferometer channels are correlated sufficiently closely with the gravity wave channel to serve as vetoes for times when triggers may have been recorded by the inspiral templates. Tools that will be used include the glitch monitor PTmon that has been tested extensively against simulations, Matlab scripts, and the LIGO tools' package Diagnostic Test Tools that displays data frames, filtered if desired. The same tools will be used in conjunction with studies of the strongest inspiral triggers that are not vetoed. The detective work involved is exciting but very time-consuming. It will be ideal for undergraduates, and offer them the opportunity of making a real contribution to a major scientific project. This award will also support the running of the inspiral analysis code to assess the triggers produced from preliminary samplings of the data to select parameters and thresholds that eliminate most of the triggers without risk of removing a real inspiral signal. Automating the process of vetoing inspiral event candidates that are really due to instrumental glitches is a high priority for the Inspiral Analysis Group and will be a part of this project. The ability to distinguish between instrumental glitches and true gravitational wave signals is a key component to the search for gravitational waves by LIGO.