1. LSC Meeting Aug 2006 Review of the S2 S3 S4 GRB/GWB Search Brian O’Reilly for the Burst Review Group

2. LSC Meeting Aug 20062 Current Status of Search l Analysis is complete l Draft paper still missing some sections To be incorporated: »Technical report for energetics and interpretation »Technical report for astrophysical population study l Study of systematic errors still needs to be done l Comments on first draft have been made

3. LSC Meeting Aug 20063 Current Status of Review

4. LSC Meeting Aug 20064 Statistical Tests… Binomial Test: Designed to detect a number of weak signals With injections: P = 4.5%Null hypothesis: P = 48% locations of injections

5. LSC Meeting Aug 20065 More Statistical Tests… cumulative probability average of max-cc values on-source average off-source averages Empirical Significance: Average max-cc values and compare to averages of off-source values — assume normal distribution Null hypothesis: P = 35%

6. LSC Meeting Aug 20066 Yet More Statistical Tests! Rank-Sum Test: Compares on-source median with off-source median cumulative probability max-cc value distribution of max-cc values Null hypothesis: P = 59%

7. LSC Meeting Aug 20067 Why so many? l Issue: too many tests of null hypothesis? l Argument in paper: »Need to show this! Investigation underway. Binomial TestP = 48% Empirical SignificanceP = 35% Rank-Sum TestP = 59%

8. LSC Meeting Aug 20068 Systematic Errors calibration errors fit uncertainty any systematics here? Example:

9. LSC Meeting Aug 20069 Missing Section: Discussion l How do you interpret results in terms of GW energy? l Depends on details of the radiation! »Polarization (linear vs. circular) »Emission pattern (isotropic vs. “beamed”) l Need to decide how to present results… »Supernovae / linearly-polarized / long-GRBs: »Binary merger / circularly polarized / short-GRBs: Need to check equations!

10. LSC Meeting Aug 200610 Population Study l Constrain some aspect of GRB population, e.g., energy emitted in gravitational waves l Requires further assumptions about population »In particular need the distance / redshift distribution (long GRBs: get from star formation rate) l Do we want this level of detail in this paper? redshift distribution cumulative redshift distribution approx. limit of sensitivity one in a million GRBs visible