Binary Black Holes in Stationary Orbits

We show that under certain astrophysical conditions a binary system consisting of two compact objects can be stabilized against indefinite shrinking of orbits due to the emission of gravitational radiation. In this case, the lighter binary companion settles down to a stable orbit when the loss of the angular momentum due to gravitational radiation becomes equal to its gain from the accreting matter from the disk around the more massive primary. We claim that such systems can be stable against small perturbations and can be regarded as steady emitters of gravitational waves of constant frequency and amplitude. Furthermore, X-rays emitted by the secondary can also produce astrophysically interesting situations when coupled with gravitational lensing and Doppler effects. It is well known that a binary system is unstable against gravitational radiation. The radiation carries away both energy as well as angular momentum and the orbits shrink indefinitely. In the case of active galaxies and Quasars, it is possible to envisage a situation, such that there is a large accretion disk (∼ 10 Schwarzschild radius) around the central black hole (of mass M1 ∼ 10 6−9M⊙) and a large number of smaller objects (of mass M2 ∼ 0.1 − 100M⊙) such as ordinary stars, white dwarfs, neutron stars and black holes orbiting around it at various orbits.