Scientific motivation –Measurement and characterization of gravitational radiation –Special interest in “burst” sources, especially in association with gamma-ray bursts (GRBs) or supernovae. Focus on Initial LIGO; our work equally relevant to AdLIGO Proposed research: Continue what we do now, but more so. –Characterize and minimize environmental influences on detectors –Carry out analyses to search for gravitational radiation Fully integrated within the LSC –Bursts analysis group –Detector Characterization Group –Commissioning Group Resources required: personnel, travel, equipment Outreach

PAC 19, LHO 2 Senior Personnel Jim Brau, Professor, PI Ray Frey, Professor, co-PI David Strom, Professor Robert Schofield, Sr. Research Associate, co-PI, 0.6 FTE on LIGO leads the detector-related activities – half-time on site at LHO Postdocs Isabel Leonor, leads the GRB analysis effort Proposed 2 nd postdoc, resident at LLO Graduate students Emelie Harstad, 3 rd year, detector characterization; 30% at LHO Masahiro Ito, PhD expected 2006, supernova search; 3 years at LHO Rauha Rahkola, PhD expected 2006, pulsed GRB search, 2+ years at LHO Personnel

PAC 19, LHO 3 Gravitational Radiation and Gamma-ray Bursts GRB HETE-2 BATSELong-duration GRBs Stronger afterglows → z A few well-measured afterglows → “hypernovae” Short-duration GRBs Until 2005, no measured z’s → enter SWIFT A few GRBs → “compact binary mergers” Oct 6, 2005

PAC 19, LHO 4 In either case, we expect associated gravitational radiation  Compact binaries are efficient gravitational radiators  Supernovae probably (much) less so – but who knows? Hence, since we know when the signal should arrive (give or take a minute), then we have a cleaner search → “externally triggered search” GRBs (contd) But, a (big) problem: GRBs are very distant. Note: sample bias Back of envelope calculations: At S5 sensitivity, we are sensitive to < 1 solar mass  c 2 of gravitational radiation at 35 Mpc for short-duration bursts.

PAC 19, LHO 5 Fully condition data; insert time lag as necessary, given the GRB position Form cross-correlation, integrate over 25 ms or 100 ms On-source data: (trigger – 120 s) to (trigger + 60 s) Off-source: 3 hours surrounding on-source segments Retain “loudest” cc in 180 s Test if on-source cc is consistent with the (off-source) bkgd. GRB analysis (I. Leonor)

6 S2,S3,S4 Results Connect max cc to upper limit in h rss strain for each GRB using injected signals. Two types of results: 1.Single events: outliers (discovery)? No. So form individual limits. 2.Statistical methods – weak signals:  Look at most significant sub-sample of events – are they consistent with background? (binomial “tail” test)  Can test if whole sample is consistent with background – assume some source model (e.g. standard candle)  FMR Method-- S. Mohanty, UT Brownsville

PAC 19, LHO 7 Getting the satellite triggers (SWIFT, HETE, Integral) - R. Rahkola 1-3 min. typical latency

PAC 19, LHO 8 S5 GRBs Can automate trigger collection and full analysis to run  real time (I. Leonor)

PAC 19, LHO 9 GRB single-event search published in PRD  Analysis led by S. Marka Search for all GRBs in S2, S3, and S4 -- I. Leonor  Technical note nearly complete  Formal LSC review starting  Draft paper very soon – To include single GRB results as well as population results (S. Mohanty) Near real-time analysis -- I. Leonor  Same method and code as the offline analysis  Tested successfully in S4; running now in S5   1 hour latency (needs data streams from both sites) S5: expect sample of  150 GRBs (mostly SWIFT) GRB-triggered Search Summary

PAC 19, LHO 10 Optimal filter supernova search – M. Ito  150 simulated waveforms from DFM, ZM, BO Looking at diagonal and off- diagonal terms Comparison to unmodeled bursts search in progress

PAC 19, LHO 11 S4 pulsed-GRB search – R. Rahkola Optimizes SNR as fn of mask parameters. Also useful for quasi-periodic waveforms.

PAC 19, LHO 12 Efforts led by R. Schofield, based 50% at LHO (2 weeks out of every 4) 1.Some projects with major consequences  Acoustic coupling mitigation  Magnetic couplings  Seismic up-conversions  Dust glitches All of these require quantitative characterization of environmental couplings to the interferometers (“PEM injections”) 2.A large number of smaller projects which improved detector performance or explained a feature of the data (See the proposal.) Characterization and mitigation of Environmental Influences

PAC 19, LHO 13 Acoustic injections

PAC 19, LHO 14 Observed acoustic couplings (2003)

PAC 19, LHO 15 Acoustic mitigation – between S2 and S3 runs R. Schofield

PAC 19, LHO 16 Acoustic mitigation result

PAC 19, LHO 17 Magnetic field Injections Generating coil

PAC 19, LHO 18 R. Schofield Magnetic coupling (contd)

PAC 19, LHO 19 Magnetic coupling (contd)

PAC 19, LHO 20 Up-conversion of low frequency seismic noise seismic noise from distant excavation night spectrum excites stack modes in AS_Q up-conversion reduces interferometer sensitivity night spectrum

PAC 19, LHO 21 Up-conversion depends on stack motion not floor motion. Small shaker on cross-beam and large shaker on floor adjusted to produce similar optic motion......produce similar up-conversion even though floor motion differs by 10.

PAC 19, LHO 22 Crab GW frequency Pump shut downPump left on Protecting sensitivity to the Crab Pulsar Also: Found lines in VME crates (fans) which were affecting stochastic measurements

PAC 19, LHO 23 Offsite seismic influences f = Hz; also appeared at in AS_Q

PAC 19, LHO 24 Glitches due to dust at asym. port optical table Glitch rate reduced by factor 50

PAC 19, LHO 25 Cosmic ray detector 1.Test mass momentum 2.Test mass heating 3.Test mass chargeup Expectation: no effects, except possibly from 3 in AdLIGO → Verify!

PAC 19, LHO 26 Cosmic rays (contd) The biggest event in S4 signal equivalent to  300 muons 3/16/05 15:23 UTC High-gain channels saturating (that’s OK) This is expected to be  1000 smaller than that which could fake a GW event in AdLIGO due to mechanisms 1 or 2. However, possibly see (or constrain) the charge effect in S5. (Sum over many CR events.) and check lack of 1 or 2.

PAC 19, LHO 27 glitchMon DMT (M. Ito)  Simple time-domain glitch finder – used primarily in control room suspensionMon DMT (B. Stubbs, R. Rahkola)  Detects swinging (transverse) optics, e.g. rung up by earthquake dewarMon DMT (E. Harstad)  Detects glitches due to diurnal thermal creaks in cold trap dewars eqMon DMT (R. Rahkola)  Control room supplement to geophysical web information RDS development and organization (I. Leonor)  Reduced data sets (several levels; channels removed/downsampled) Signal injection scripts (I. Leonor)  Hardware and software GRB notification (R. Rahkola) “Online” and offline GRB analysis (I. Leonor) Software tools for detector characterization and analysis

PAC 19, LHO 28 Environmental influences and detector characterization... Continue!  Between science runs: continue as before  During runs: PEM injections every few months – monitor and apply to analyses (e.g. acoustic coupling and S2 airplane event) Track down artifacts found by analysis groups (lines, crab pulsar protection, identify possible vetos)  The demand for these activities will continue for initial LIGO and on to AdLIGO. (We need to develop plan for required upgrades of monitoring instrumentation for AdLIGO.) We propose extending the above to LLO  Endorsed enthusiastically by the LLO Director GRB and bursts analyses... Continue! Proposal

PAC 19, LHO 29 Undergraduate participation in LIGO-related research Oregon apprenticeships in Science and Engineering Program  Talented high school students from throughout Oregon QuarkNet program (joint NSF/DoE)  High school physics teachers learn about research (annual workshops) Public lectures  Jim Brau: 500 attendees  Ray Frey: IEEE talk for students Eugene Register-Guard  Front page May 22, 2005: “A place of utmost gravity...” Outreach (highlights)