General Relativistic Magnetohydrodynamic Simulations of Neutron Stars and Black Holes

Bruno Giacomazzo

March 12, 2012

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Abstract: Neutron star binaries (BNSs) and binary black holes (BBHs) are among the most powerful sources of gravitational waves (GWs). Neutron star mergers are also thought to be behind the central engine of short gamma-ray bursts (GRBs) and a contemporary detection of a GW by advanced LIGO/Virgo together with a short GRB will allow us to finally unveil the engine that powers these phenomena. In the first part of my talk I will review some recent results obtained using my fully general relativistic magnetohydrodynamic code Whisky and that describe the effect of magnetic fields on the merger of BNSs, their GW signals and their possible connection to short GRBs. In the second part I will instead show new results describing the dynamics of a magnetized plasma during the merger of super-massive black holes. Super-massive BBHs are produced by the mergers of galaxies and they are among the most powerful sources of GWs that can be detected by eLISA. In many cases it is believed that the merger may happen in presence of matter and magnetic fields and in this case the GW signal may be accompanied by an electro-magnetic counterpart.