A Galactic Scale Gravitational Wave Observatory

Maura McLaughlin, West Virginia University

Timing an array of pulsars could result in the detection of a stochastic gravitational wave background, most likely resulting from an ensemble of supermassive black hole binaries, and is already constraining models for galaxy formation and the tension of cosmic strings. Pulsar timing arrays are also sensitive to continuous and burst gravitational wave sources. I will give an overview of the observational strategies and detection algorithms used for these various source classes. I will then describe the efforts of the North American Nanohertz Observatory for Gravitational Waves (NANOGrav), a collaboration which monitors an array of over 40 millisecond pulsars with the Green Bank Telescope and Arecibo Observatory. I will describe the dramatic gains in sensitivity that are expected from discoveries of many new millisecond pulsars, more sensitive instrumentation, improved detection algorithms, and international collaboration and discuss the likely time to gravitational wave detection using pulsar timing under various scenarios.