Developing Tools for Multimessenger Gravitational Wave Astronomy
The Marcel Grossmann triennial meetings are focused on reviewing developments in gravitation and general relativity, aimed at understanding and testing Einstein’s theory of gravitation. The 15th meeting (Rome, 2018) celebrated the 50th anniversary of the ﬁrst neutron star discovery (1967), and the birth of relativistic astrophysics. Another discovery of the same caliber is the detection of the binary neutron star GW170817 in 2017 – almost as if to celebrate the same jubilee – marking the beginning of multi-messenger gravitational wave astronomy. We present work in progress to craft open-sourced numerical tools that will enable the calculation of electromagnetic counterparts to gravitational waveforms: the GiRaFFE (General Relativistic Force-Free Electrodynamics) code. GiRaFFE numerically solves the general relativistic magnetohydrodynamics system of equations in the force-free limit, to model the magnetospheres surrounding compact binaries, in order (1) to characterize the nonlinear interaction between the source and its surrounding magnetosphere, and (2) to evaluate the electromagnetic counterparts of gravitational waves, including the production of collimated jets. We apply this code to various conﬁgurations of spinning black holes immersed in an external magnetic ﬁeld, in order both to test our implementation and to explore the eﬀects of (1) strong gravitational ﬁeld, (2) high spins, and (3) tilt between the magnetic ﬁeld lines and black hole spin, all on the ampliﬁcation and collimation of Poynting jets. We will extend our work to collisions of black holes immersed in external magnetic ﬁeld, which are prime candidates for coincident detection in both gravitational and electromagnetic spectra.
Maria C. Babiuc Hamilton, "Developing Tools for Multimessenger Gravitational Wave Astronomy", in MG15 (Rome, 2018).