Session 84 - Neutron Stars and Their Friends.
Oral session, Thursday, June 13
Historical Society,

[84.04] Hydrodynamic Simulations of Mergers of Neutron Stars and Newtonian Black Holes

W. H. Lee, W. Klu\'zniak (UW-Madison)

We have performed Newtonian smooth particle hydrodynamic simulations for the merger of a 1.4 M_ødot neutron star with a black hole in a compact binary system. The neutron star is modeled as a stiff polytrope and the black hole is treated as a point mass. Initial results for a mass ratio q=M_NS/M_BH=1 (Lee amp; Klu\'zniak, 1995), have shown that a hydrodynamical instability leads to violent disruption of the system on a dynamical timescale. We present preliminary results for different mass ratios (q \leq 1), which exhibit qualitatively different behavior. The gravitational radiation waveforms produced during the event are computed in the quadrupole approximation. Implications for the likelihood of such events being the source of gamma ray bursts are discussed.

\small Lee, W.H., Klu\'zniak, W., \emActa Astron., \bf45, 1995, 705.