The First Two Years of Electromagnetic Follow-up with Advanced LIGO and Virgo
We anticipate the first direct detections of gravitational waves (GWs) with Advanced LIGO and Virgo later this decade. Though this groundbreaking technical achievement will be its own reward, a still greater prize could be observations of compact binary mergers in both gravitational and electromagnetic channels simultaneously. During Advanced LIGO and Virgo's first two years of operation, 2015 through 2016, we expect the global GW detector array to improve in sensitivity and livetime and expand from two to three detectors. We model the detection rate and the sky localization accuracy for binary neutron star (BNS) mergers across this transition. We have analyzed a large, astrophysically motivated source population using real-time detection and sky localization codes and higher-latency parameter estimation codes that have been expressly built for operation in the Advanced LIGO/Virgo era. We show that for most BNS events, the rapid sky localization, available about a minute after a detection, is as accurate as the full parameter estimation. We demonstrate that Advanced Virgo will play an important role in sky localization, even though it is anticipated to come online with only one-third as much sensitivity as the Advanced LIGO detectors. We find that the median 90% confidence region shrinks from ~500 deg^2 in 2015 to ~200 deg^2 in 2016. A few distinct scenarios for the first LIGO/Virgo detections emerge from our simulations.
© 2014 American Astronomical Society. Received 2014 April 23; accepted 2014 September 4; published 2014 October 17. L.P.S. and B.F. thank generous support from the National Science Foundation (NSF) in the form of Graduate Research Fellowships. B.F. acknowledges support through NSF grants DGE-0824162 and PHY-0969820. A.L.U. and C.P. gratefully acknowledge NSF support under grants PHY-0970074 and PHY-1307429 at the University of Wisconsin–Milwaukee (UWM) Research Growth Initiative. J.V. was supported by the research programme of the Foundation for Fundamental Research on Matter (FOM), which is partially supported by the Netherlands Organisation for Scientific Research (NWO), and by Science and Technology Facilities Council (STFC) grant ST/K005014/1. P.G. is supported by a NASA Postdoctoral Fellowship Administered by the Oak Ridge Associated Universities. GSTLAL analyses were produced on the NEMO computing cluster operated by the Center for Gravitation and Cosmology at UWM under NSF Grants PHY-0923409 and PHY-0600953. The BAYESTAR analyses were performed on the LIGO–Caltech computing cluster. The MCMC computations were performed on Northwestern's CIERA High-Performance Computing cluster GRAIL. We thank Patrick Brady, Vicky Kalogera, Erik Katsavounidis, Richard O'Shaughnessy, Ruslan Vaulin, and Alan Weinstein for helpful discussions. This research made use of Astropy^(21) (Robitaille et al. 2013), a community-developed core Python package for Astronomy. Some of the results in this paper have been derived using HEALPix (Gόrski et al. 2005). Public domain cartographic data is courtesy of Natural Earth22 and processed with MapShaper.23 BAYESTAR, LALINFERENCE_NEST, and LALINFERENCE_MCMC are part of the LIGO Algorithm Library Suite24 and the LIGO parameter estimation package, LALINFERENCE. Source code for GSTLAL^(25) and LALINFERENCE^(26) are available online under the terms of the GNU General Public License. LIGO was constructed by the California Institute of Technology and Massachusetts Institute of Technology with funding from the NSF and operates under cooperative agreement PHY-0757058. This is LIGO document number LIGO-P1300187-v24.
Published - 0004-637X_795_2_105.pdf
Submitted - 1404.5623v5.pdf