 General programme, activity sheet


 



Thursday 21 March, 2013 12:00 to 12:30 

Conference 
Magnetized Accretion onto Inspiraling Binary Black Holes. Speaker: Bruno Mundim, AEI, Postdoc
Authors: S. Noble, Bruno C. Mundim, H. Nakano, M. Campanelli, Y. Zlochower, J. Krolik, N. Yunes
Fully general relativistic numerical solutions to magnetized accretion onto black hole binaries are computationally very expensive. Current efforts are limited to very short binary separations. On the other extreme, however, pointparticle Newtonian mechanics is used to accurately model accretion onto binaries with very large separations. In order to bridge the gap between these two extreme regimes, we construct a global timedependent analytic approximation to the binary spacetime metric by asymptotically matching analytic metric approximations with different regions of validity. We apply black hole perturbation theory in the inner zone; 2.5 postNewtonian theory in the near zone; and postMinkowskian theory consistent with postNewtonian theory in the far zone. In addition, we employ 3.5 postNewtonian equations of motion to accurately describe the binary dynamics in its inspiral phase. We find the spacetime to be accurate to the expected leading postNewtonian order, and demonstrate its reasonably small violations of the Hamiltonian and momentum constraints. With our PN gravity model, we evolve a magnetized disk using a modern general relativistic magnetohydrodynamics code. We show that many aspects of the disk follow the binary inward as its separation diminishes up until when the binary shrinkage timescale becomes smaller than the inflow timescale at the inner edge of the disk. We also present predictions for the bolometric luminosity using our radiative cooling function as a proxy for emissivity. Morning Sessions Place: Salon Grados
