Quick Search:
Author: Title/Abstract: Vol./No: Page:

## Prog. Theor. Phys. Vol. 86 No. 1 (1991) pp. 73-88

[ Full Text PDF : FREE ACCESS (795K) ]

# Gravitational Radiation from Coalescing Binary Neutron Stars. IV

## — Tidal Disruption —

Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606
*National Laboratory for High Energy Physics, Tsukuba 305

### Abstract:

We have performed three numerical simulations of coalescence of binary neutron stars using a Newtonian hydrodynamics code including the effect of radiation reaction due to emission of gravitational waves. We use the Cartesian coordinate system (x, y, z) with a 141 ×141 ×131 grid and assume the reflection symmetry with respect to z = 0 plane. In the first simulation, we start the calculation from a rotational equilibrium of two neutron stars of mass m1 = m2 = 0.85 M which touches with each other. This corresponds to a fission model of collapse of a rapidly rotating core. The radiated energy is 0.8% of the rest mass and the maximum amplitude of the gravitational waves is 2 ×10-21 if it occurs at a distance of 10 Mpc. The ratio of the rotational energy to the gravitational energy T/W is ∼ 0.15 in the final stage of the numerical simulation. Since this value is greater than the secular instability limit, non-axisymmetric instability with the emission of gravitational waves occurs. This is quite different from the case with m1 = m2 = 1.49 M in a previous paper. In the other two simulations, two neutron stars have different masses; m1 = 1.70 M, m2 = 1.28 M and m1 = 1.83 M, m2 = 0.97 M, respectively. We assume that the system is in a rotational equilibrium at first. Calculations are started when separation between neutron stars are 19 km and 21 km, respectively. In both cases, tidal disruption of neutron star of smaller mas occurs. The radiated energy amounts to 2.9% and 2.3% of the total rest mass, respectively. The maximum amplitude of the gravitational waves at a distance of 10 Mpc is 4.4 ×10-21 and 3.4 ×10-21.

DOI : 10.1143/PTP.86.73

[ Full Text PDF : FREE ACCESS (795K) ] Citation:

### References:

1. K. Oohara and T. Nakamura, Prog. Theor. Phys. 83 (1990), 906 [PTP](Paper III).
2. D. Backer and S. Kulkarni, Phys. Today 43 (1990), 26.
3. J. H. Taylor, Talk at the Texas/ESO and CERN Symposium on Relativistic Astrophysics, Brighten, UK, December 1990.
4. J. P. A. Clarke, E. P. J. van den Heuvel and W. Suntantyo, Astron. Astrophys. 72 (1979), 120.
5. K. Oohara and T. Nakamura, Prog. Theor. Phys. 82 (1989), 535 [PTP](Paper I).
6. T. Nakamura and M. Fukugita, Astrophys. J. 337 (1989), 466[CrossRef].
7. T. Nakamura and H. Sato, Phys. Lett. 86A (1981), 318.
R. F. Stark and T. Piran, Phys. Rev. Lett. 55 (1985), 891[APS].
8. T. Nakamura, Prog. Theor. Phys. 70 (1983), 1144[PTP].
9. For example, G. Chanmugam and K. Brecher, Nature 329 (1987), 696[CrossRef].
10. R. Narayan and R. Popham, Astrophys. J. 346 (1989), L25[CrossRef].
11. L. Blanchet, T. Damour and G. Schäfer, Mon. Not. R. Astron. Soc. 242 (1990), 289.
12. K. Oohara and T. Nakamura, Prog. Theor. Phys. 81 (1989), 360[PTP].
K. Oohara and T. Nakamura, in Frontiers of Numerical Relativity, ed. D. Hobill, C. Evans and S. Finn (Cambridge University Press, 1989), p. 74.
13. S. Chandrasekhar, Ellipsoidal Figures of Equilibrium (Yale University Press, 1969).
S. Chandrasekhar, Astrophys. J. 161 (1970), 561[CrossRef].
14. T. Nakamura, Prog. Theor. Phys. 81 (1989), 1006[PTP].
15. L. Smarr, in Sources of Gravitational Waves, ed. L. Smarr (Cambridge University, Press, Cambridge, 1979), p. 245.
16. R. F. Stark and T. Piran, Phys. Rev. Lett. 55 (1985), 891[APS].
17. T. Nakamura, K. Oohara and Y. Kojima, Prog. Theor. Phys. Suppl. No. 90 (1987), 1[PTP].

### Citing Article(s) :

1. Progress of Theoretical Physics Vol. 87 No. 4 (1992) pp. 879-890 :
Some Comments on the Origin of Gamma Ray Bursts
Takashi Nakamura, Noriaki Shibazaki, Yoshio Murakami and Atsumasa Yoshida
2. Progress of Theoretical Physics Vol. 87 No. 5 (1992) pp. 1139-1157 :
Metric Perturbations Induced by a Particle Falling into a Schwarzschild Black Hole. I
Masaharu Shibata and Takashi Nakamura
3. Progress of Theoretical Physics Vol. 88 No. 2 (1992) pp. 307-315 :
Gravitational Radiation from Coalescing Binary Neutron Stars. V
Ken-ichi Oohara and Takashi Nakamura
4. Progress of Theoretical Physics Vol. 88 No. 6 (1992) pp. 1079-1095 :
Coalescence of Spinning Binary Neutron Stars of Equal Mass
Masaru Shibata, Takashi Nakamura and Ken-ichi Oohara
5. Progress of Theoretical Physics Vol. 89 No. 4 (1993) pp. 809-819 :
Coalescence of Spinning Binary Neutron Stars with Plunging Orbit
Masaru Shibata, Takashi Nakamura and Ken-ichi Oohara
6. Progress of Theoretical Physics Vol. 107 No. 2 (2002) pp. 265-303 :
Gravitational Waves from the Merger of Binary Neutron Stars in a Fully General Relativistic Simulation
Masaru Shibata and Kōji Uryū
7. Progress of Theoretical Physics Supplement No.128 (1997) pp. 123-181 :
Chapter 2. Post-Newtonian Approximation