Multipolar analysis of spinning binaries

Understand

We present a preliminary study of the multipolar structure of gravitational radiation from spinning black hole binary mergers.

• We consider three different spinning binary configurations: (1) one "hang-up" run, where the black holes have equal masses and large spins initially aligned with the orbital angular momentum; (2) seven "spin-flip" runs, where the holes have a mass ratio q=4, the spins are anti-aligned with the orbital angular momentum, and the initial Kerr parameters of the holes j_1=j_2=j_i are fine-tuned to produce a Schwarzschild remnant after merger; (3) three "super-kick" runs where the mass ratio q=M_1/M_2=1, 2, 4 and the spins of the two holes are initially located on the orbital plane, pointing in opposite directions.
• For all of these simulations we compute the multipolar energy distribution and the Kerr parameter of the final hole.
• For the hang-up run, we show that including leading-order spin-orbit and spin-spin terms in a multipolar decomposition of the post-Newtonian waveforms improves the agreement with the numerical simulation.