Update on the intermediate pipeline Eric Thrane March 16, 2010 LVC Meeting, Arcadia

2 Contributors Alessandra Corsi, Antonis Mytidis, Ben Owen, Bernard Whiting, Christian Ott, Eric Chassande-Mottin, Eric Thrane, Ignacio Santiago, Ik Siong Heng, James Clark, Mark Edwards, Michael Coughlin, Nelson Christianson, Patrick Sutton, Peter Kalmus, Peter Raffai, Shanxu Shi, Shivaraj Kanhasamy, Stefanos Giampanis, Steven Dorsher, Vuk Mandic, Warren Anderson ~12 active members.

3 Overview The intermediate pipeline Astrophysical sources Two models of long GRBs Data quality

4 The intermediate pipeline The stochastic group generates “intermediate data” frames. –26 s long segments with 0.25 Hz resolution –Contain CSD and PSD’s for, e.g., H1L1. The main objective of the IM pipeline is to look for GW transients on timescales ranging from  t=26s to weeks. The secondary objective is to provide a tool for DQ studies (probing the same timescales).

5 Looking for statistically significant correlations Whether we are studying GWs or instrumental effects, the procedure is as follows: Generate ft-map with pixel values given by: Uncorrelated data described by PDF with mean=0 and var=1. Clusters of bright pixels indicate correlation. f (Hz) t (s) SNR

6 Astrophysical sources Supernovae and long GRBs: proto-neutron star (PNS) convection, dynamical rotational instabilities, r-modes in young neutron stars, Chandrasekhar-Friedman-Schutz (CFS) rotational instability, torus instabilities, torus excitations Short GRBs: dynamical rotational instabilities, CFS rotational instabilities, r- modes Isolated neutron stars: pulsar glitches, SGR flares

7 Preliminary targets: long GRBs Chose two models of GW emission to perform MC analysis and obtain sensitivity estimates: –Torus excitations in long GRBs (van Putten) Predicts high h: possibility of constraining model Look with Radon algorithm (Steven Dorsher) –Fragmentation of accretion disk in long GRBs (Piro & Pfahl) Look with Locus algorithm (narrowband: Peter Raffai) …and Box algorithm (broadband: Shivaraj Kandhasamy) Results to be summarized in method paper.

8 Two models M. van Putten long GRBs –duration: ~ s –line in ft-space near ~kHz –10% of black hole energy goes in to GWs: ~6x10 53 ergs –h~ at 100 Mpc! Piro & Pfahl accretion disk fragmentation –duration: hundreds of seconds –narrowband (CBC-type signal) and broadband signals possible M. van Putten, ApJ, 575 L71 (2002) M. van Putten, PRL, (2001) A. L. Piro & E. Pfahl, ApJ, (2007)

9 Recovery/Sensitivity studies Create waveform and calculate contribution to ft-map. Recover injection. Determine distance d 0 at which CL = 99% with 50% efficiency (assume reasonable parameter values). Calculate confidence interval.

10 Toy model example Used spectrum predicted for proto- neutron star (PNS) convection*. –We extend the duration beyond predicted value of ~2-5 s. Calculations in progress for long GRB models. S. Kandhasamy * E. Müller et al, ApJ, , (2004)

11 Are the data well behaved? We are studying the distribution of the SNR statistic used by our search algorithms (B. Whiting & A. Mytidis). Expect  =0 &  =1, but we see evidence of non-stationary noise at some frequencies. These frequencies are not identified by coherence analysis.  SNR (f) f (Hz) 60 Hz harmonics violin resonances Useful information for stochastic analyses! calibration sidebands

12 Right: histogram of SNR (removed frequencies with  ≠1). Distribution is not normal (but close). Studying expected and measured distribution. Preliminary result: distribution well fit by sum of two Gaussians. detail SNR Gaussian fit Characterizing the PDF B. Whiting & A. Mytidis

13 Other data quality studies N. Christianson and M. Coughlin have started two new IM pipeline projects. H1H2 –IM data generated –Investigating possibility/usefulness of removing transients in future stochastic analyses. H1-PEM –IM data generated…validation in progress –Look for coherence with PEM channels –Use for commissioning and data cleanup

14 Next steps Injection recovery and sensitivity estimation study. Determine expected/measured PDF for SNR. Matched filtering comparison? Complete method paper. S5 analysis DQ studies are ongoing.