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LIGO-G050274-00-W Gregory Mendell, LIGO Hanford Observatory on behalf of the LIGO Scientific Collaboration StackSlide Summary LSC Meeting, August 2005 http://www.ligo.caltech.edu Supported by the National Science Foundation LIGO-G050374-00-W
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LIGO-G050274-00-W Incoherent Power Averaging Break up data into M segments; FFT each segment. Track the frequency. StackSlide: add the power weighted by the noise inverse. Hough: add 1 or 0 if power is above/below a cutoff. PowerFlux: add power using weights that maximize SNR Frequency Time LIGO-G050374-00-W
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LIGO-G050274-00-W Highlights at the last LSC meeting. Added code and options to generate Sky Bands perpendicular to any point on the sky (e.g., Earth’s average orbital acceleration vector ala PowerFlux, the galactic pole for a search of the galactic plane, etc…) Added code and options to clean SFTs in memory (borrowed functions from Hough SFTbin.c and SFTbin.h). Added code and options to extend pipeline to run follow-up iterated Monte Carlo Simulations to converge on desired confidence Upper Limits. Produced further code validation results. Produced example results for S3 H1data for the 570 to 580 Hz band, without spindown. LIGO-G050374-00-W
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LIGO-G050274-00-W Highlights since the last LSC meeting. Code Review Started (three review telecons since June). Review web page: http://www.ligo- wa.caltech.edu/~gmendell/PULG/StackSlideUtilities/review/ StackSlideReviewPage.html Improved Monte Carlo search based on reviewer suggestions. (Still planning to implement methods to speed up MC.) Fixed issues with cleaning code (SFTbin.c). Fixed or will fix, bugs in MC simulations with spindown and sky parameter space placement found by Joe Betzweiser. Looked for 1 Hz harmonics and other outliers in the S4 H2, H1, and L1 data. See h(t) talk by Mike Landry. Produced example S4 H1 and L1 results, with/without cleaning. LIGO-G050374-00-W
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LIGO-G050274-00-W Improved Monte Carlo Simulations Old: 1. select parameter space point, 2. generate random mismatch, 3. inject, and 4. search nearest point (in Euclidean sense). New: 1. generate random point within the parameter space, 2. inject, 3. search surrounding points (in Euclidean sense). LIGO-G050374-00-W
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LIGO-G050274-00-W S4 One Hz Harmonics; see h(t) talk by Mike Landry.
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LIGO-G050274-00-W StackSlide Sky Patches For S4 LIGO-G050374-00-W
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LIGO-G050274-00-W S4 H1 and L1 One Hz Harmonics 570 to 580 Hz Band LIGO-G050374-00-W
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LIGO-G050274-00-W S4 H1 Example Loudest Events LIGO-G050374-00-W
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LIGO-G050274-00-W S4 H1 Estimated Upper Limits on h 0 LIGO-G050374-00-W *Limits are for every.25 Hz band for a search over sky position, frequency, and 11 values of the first spindown parameter.
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LIGO-G050274-00-W S4 L1 Example Loudest Events LIGO-G050374-00-W
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LIGO-G050274-00-W S4 L1 Estimated Upper Limits on h 0 LIGO-G050374-00-W *Limits are for every.25 Hz band for a search over sky position, frequency, and 11 values of the first spindown parameter.
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LIGO-G050274-00-W S4 L1 “Average” vs “Worst Case” Upper Limits on h 0
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LIGO-G050274-00-W S4 L1 “Average” vs. “Worst Case” Sky Maps and Histograms Loudest Event: 1.18 LIGO-G050374-00-W
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LIGO-G050274-00-W Histogram of StackSlide Power Explained StackSlide Power = 1 + 0.5d 2 where for a signal from a triaxial ellipsoid d 2 ~ h 0 2 T sft /S n [.25(1 + cos 2 i) 2 + cos 2 i].
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LIGO-G050274-00-W Plans Short Term: Finish Pipeline that verifies Estimated ULs (done but needs tweaking) Handle PowerFlux Style Sky Bands (done) Speed up MC (still 1 st priority) Use new version of the StackSlide function (tested and it works!) Start StackSlide of F-statistic (priority before S5) Finish validations & test code (Code Review Started!) Produce S4 results ( preliminary results started) Ongoing Parameter space metric Virginia Re and Joe Betzwieser working on StackSlide binary and multiple spindown searches for CW GWs respectively. Coincidence Analysis Line Veto Studies (Will use Hough Method) Develop Hierarchical Searches Optimization Generate a Complete Detection Pipeline LIGO-G050374-00-W
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