We study the gravitational wave emission of equal-mass neutron stars in binary orbits as the stars approach the inner most last stable circular orbit. We illustrate the extraction of gravitational wave forms in a sequence of quasi-circular orbit simulations including the general relativistic hydrodynamic response of the stars. We compare the computed results with the Newtonian and post Newtonian results and show that substantial differences can arise as the orbits approach the final inspiral. | Communications in Physics, Vol. 25, No. 4 (2015), pp. 299-308 DOI: GRAVITATIONAL WAVEFORMS FROM MULTIPLE-ORBIT SIMULATIONS OF BINARY NEUTRON STARS NGUYEN QUYNH LAN Hanoi National University of Education, 136 Xuan Thuy, Cau Giay and Joint Institute for Nuclear Astrophysics (JINA), University of Notre Dame, Notre Dame, Indiana 46556, USA IN-SAENG SUH Center for Astrophysics, Department of Physics and Center for Research Computing, University of Notre Dame, Notre Dame, Indiana 46556, USA GRANT J. MATHEWS AND J. REESE HAYWOOD Center for Astrophysics, Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, USA E-mail: nquynhlan@ Received 26 October 2015 Accepted for publication 12 December 2014 Abstract. We study the gravitational wave emission of equal-mass neutron stars in binary orbits as the stars approach the inner most last stable circular orbit. We illustrate the extraction of gravitational wave forms in a sequence of quasi-circular orbit simulations including the general relativistic hydrodynamic response of the stars. We compare the computed results with the Newtonian and post Newtonian results and show that substantial differences can arise as the orbits approach the final inspiral. Keywords: binary neutron stars, numerical relativity, ADM. I. INTRODUCTION Current interferemetric gravity wave observatories such as LIGO [1], GEO600 [2], GEOHF [3, 4], TAMA300 [5] and VIRGO [6] have been taking data for some time [7–10], while a number of second generation observatories such as Advanced LIGO [11], Advanced VIRGO [12] and KAGRA [13] soon will be online. These observatories seek to detect gravity-wave emission from various sources, . from core collapse supernovae, neutron star orbits, the stochastic cosmic background, etc. [1]. Of the many systems that emit gravitational waves, compact neutron-star and/or black-hole binaries are thought to be the best candidates for detecting gravitational .
