The effects of LIGO detector noise on a 15-dimensional Markov-chain Monte Carlo analysis

Gravitational-wave signals from inspirals of binary compact objects (black holes and neutron stars) are primary targets of the ongoing searches by groundbased gravitational-wave (GW) interferometers (LIGO, Virgo and GEO-600). We present parameter estimation results from our Markov-chain Monte Carlo code SPINSPIRAL on signals from binaries with precessing spins. Two data sets are created by injecting simulated GW signals either into synthetic Gaussian noise or into LIGO detector data. We compute the 15-dimensional probabilitydensity functions (PDFs) for both data sets, as well as for a data set containing LIGO data with a known, loud artefact (‘glitch’). We show that the analysis of the signal in detector noise yields accuracies similar to those obtained using simulated Gaussian noise. We also find that while the Markov chains from the glitch do not converge, the PDFs would look consistent with a GW signal present in the data. While our parameter estimation results are encouraging, further investigations into how to differentiate an actual GW signal from noise are necessary. PACS numbers: 02.50.−r, 02.70.Uu, 04.30.Tv, 04.80.Nn, 95.85.Sz (Some figures in this article are in colour only in the electronic version) 0264-9381/10/114009+10$30.00 © 2010 IOP Publishing Ltd Printed in the UK & the USA 1 Class. Quantum Grav. 27 (2010) 114009 V Raymond et al