Moh'd S. S. Qusailah | Searcharxiv

arXiv2008

Inspiralling compact binaries in quasi-elliptical orbits: The complete third post-Newtonian energy flux

The instantaneous contributions to the 3PN gravitational wave luminosity from the inspiral phase of a binary system of compact objects moving in a quasi elliptical orbit is computed using the multipolar post-Minkowskian wave generation formalism. The necessary inputs for this calculation include the 3PN accurate mass quadrupole moment for general orbits and the mass octupole and current quadrupole moments at 2PN. Using the recently obtained 3PN quasi-Keplerian representation of elliptical orbits the flux is averaged over the binary's orbit. Supplementing this by the important hereditary contributions arising from tails, tails-of-tails and tails squared terms calculated in a previous paper, the complete 3PN energy flux is obtained. The final result presented in this paper would be needed for the construction of ready-to-use templates for binaries moving on non-circular orbits, a plausible class of sources not only for the space based detectors like LISA but also for the ground based ones.

gr-qc↗

arXiv2005

Gravitational Recoil of Inspiralling Black-Hole Binaries to Second Post-Newtonian Order

The loss of linear momentum by gravitational radiation and the resulting gravitational recoil of black-hole binary systems may play an important role in the growth of massive black holes in early galaxies. We calculate the gravitational recoil of non-spinning black-hole binaries at the second post-Newtonian order (2PN) beyond the dominant effect, obtaining, for the first time, the 1.5PN correction term due to tails of waves and the next 2PN term. We find that the maximum value of the net recoil experienced by the binary due to the inspiral phase up to the innermost stable circular orbit (ISCO) is of the order of 22 km/s. We then estimate the kick velocity accumulated during the plunge from the ISCO up to the horizon by integrating the momentum flux using the 2PN formula along a plunge geodesic of the Schwarzschild metric. We find that the contribution of the plunge dominates over that of the inspiral. For a mass ratio m_2/m_1=1/8, we estimate a total recoil velocity (due to both adiabatic and plunge phases) of 100 +/- 20 km/s. For a ratio 0.38, the recoil is maximum and we estimate it to be 250 +/- 50 km/s. In the limit of small mass ratio, we estimate V/c to be approximately 0.043 (1 +/- 20%)(m_2/m_1)^2. Our estimates are consistent with, but span a substantially narrower range than, those of Favata et al. (2004).

astro-ph↗