Using pulsars in a Galactic-scale gravitational-wave detector
At the forefront of observation astrophysics is the effort to directly detect gravitational waves (GWs), which remains a "holy grail" in validating Einstein's general theory of relativity. This is an international undertaking, involving many experiments by several large collaborations. In this talk, I will focus on the effort of the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) collaboration, which uses the distances between Earth and several millisecond-period pulsars as arms of a Galactic-scale GW detector. This "Pulsar Timing Array" is sensitive to the nanohertz frequency region of the GW spectrum, and is the only current method for studying GW emission from supermassive black hole pairs. It is therefore complementary to the larger frequency ranges probed by ground-based detectors, which will be sensitive to sources such as merging neutron-star pairs. I will discuss how we will be able to detect GWs with pulsar timing, and describe recent progress. I will also briefly describe ongoing and future instrumentation and other observational considérations that will greatly benefit this work.
Date: Jeudi, le 18 février 2016 Heure: 11:30 Lieu: Université de Montréal Pavillon Roger-Gaudry, local D-460 Contact: Pierre Bergeron