Newtonian and Post-Newtonian Simulations of Neutron Star Mergers
Abstract
Neutron Star Mergers (NSMs) are expected to be among the sources of gravitational waves that will be observed by gravitational wave detectors in the next decade. Accurate theoretical predictions of the gravitational wave signatures of events such as NSMs will be required to extract the signals from background noise. Post-Newtonian models can be applied to these systems, but full 3-d simulations are required to properly capture tidal effects, particularly in the last several orbits. We present the results of our numerical studies of NSMs with Newtonian hydrodynamics coupled to the 2.5 Post-Newtonian radiation reaction of Blanchet, Damour, and Schafer (1990). Our simulations evolve the Euler equations using a modification of the ZEUS 2-d algorithm (Stone and Norman 1992) and use a Fast Fourier Transformation method for solving the Poisson equation for the gravitational field. We describe the results of our studies of tidal instabilities in purely Newtonian simulations, and contrast these effects to those of the radiation reaction. We describe the technical difficulties we encountered in modeling NSMs, and discuss the motivation for performing these simulations in the co-rotating reference frame. We present the h_+ and h_x gravitational wave signals and luminosity produced during the coalescence. We comment on the implications of our simulations on the possibility of NSMs as a source of gamma-ray bursts. We also present a comparison between our method for modeling Newtonian NSMs and other hydrodynamic methods.
- Publication:
-
American Astronomical Society Meeting Abstracts
- Pub Date:
- December 1998
- Bibcode:
- 1998AAS...193.4213C