Dynamical Formation and Evolution of Compact Binaries

Northwestern University, Evanston IL

Investigators

Abstract

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). Coalescing compact binaries, binary star systems with black holes or neutron stars in highly relativistic orbits, are the most important potential sources of gravitational radiation for current laser interferometer detectors such as LIGO. The theoretical study of gravitational wave sources is crucial for the interpretation of data to be collected by the interferometers, and for the planning of future, more advanced detectors. Three related projects are being supported by this award: (1) Numerical calculations of the final mergers of compact binary systems containing a black hole and a neutron star, to be performed using an existing 3-D relativistic hydrodynamics code as part of an ongoing collaboration between Northwestern and Georgia Tech; (2) The development of a new parallel supercomputer code for simulating compact binary mergers in full general relativity, combining a powerful, particle-based algorithm for hydrodynamics ("smoothed particle hydrodynamics") with a fully dynamic and nonlinear treatment of space-time; (3) Stellar dynamics simulations of black holes in dense star clusters, where frequent dynamical interactions can lead to the formation of large numbers of coalescing compact binaries. Coalescing compact binaries are also important in many other areas of astrophysics, such as the study of gamma-ray bursts and the production of heavy chemical elements in galaxies. The stellar dynamics and relativistic hydrodynamics codes to be developed are general tools, which will be useful for studying many other problems involving relativistic stars and fluids. The development of new particle-based numerical algorithms for the study of highly nonlinear and complex multi-physics problems has a strong interdisciplinary character and can help establish closer ties between gravitational physics, computer science, and applied mathematics. Outreach activities are taking advantage of the resources of the nearby Adler Planetarium and Astronomy Museum in Chicago, allowing the research results and methodology to be presented to a large and diverse public.