Thursday, August 15, 20191:00 PM - 2:00 PMCNLS Conference Room (TA-3, Bldg 1690)|
Predicting Electromagnetic Counterparts to Supermassive Binary Black Hole Mergers
Supermassive binary black holes (SMBBH) are expected to form in galactic environments which should provide ample amounts of gas for them to be electromagnetically bright, making them an excellent candidate for multimessenger astrophysics following the launch of LISA. However, the question of what the electromagnetic counterpart to such a merger would be remains largely unanswered. To a zeroth order, the electromagnetic counterpart will be directly related to the amount and structure of gas in the immediate vicinity of the black holes. In this talk, we present results from a 34 million CPU hour, 3D general relativistic magnetohydrodynamic (MHD) simulation including, for the first time, individual disks of gas around each black hole, or “mini-disks”, in general relativity or MHD. We find that relativistic SMBBH accretion acts as a resonant cavity, where quasi-periodic oscillations permeate the system. These oscillations are tied to the frequency at which the black hole’s orbital phase matches a nonlinear m=1 density feature, or “lump”, in the circumbinary disk orbiting the binary pair. Furthermore, such time variability stands in stark contrast to previous calculations and could introduce distinctive, increasingly rapid, fluctuations in their electromagnetic emission.
Host: Timothy Waters