# General Relativistic Simulations of Binary Black Hole-Neutron Stars: Precursor Electromagnetic Signals

• Zachariah B. Etienne
• Vasileios Paschalidis
• Stuart L. Shapiro
University of Illinois at Urbana-Champaign

## Abstract

We perform the first general relativistic force-free simulations of neutron star magnetospheres in orbit about spinning and non-spinning black holes. We find promising precursor electromagnetic emission: typical Poynting luminosities at, e.g., an orbital separation of $\small r=6.6R_{NS}$ are $\small L_{EM}\sim6\times10^{42}(B_{NS,p} /10^{13}G)^{2}(M_{NS}/1.4M_{\odot})^{2}$erg/s. The Poynting flux peaks within a broad beam of ~ 40o in the azimuthal direction and within ~ 60o from the orbital plane, establishing a possible lighthouse effect. Our calculations, though preliminary, preview more detailed simulations of these systems that we plan to perform in the future.

## Rendering

These visualizations were created using both VisIt and ZIB Amira software [D. Stalling, M. Westerhoff, and H.-C. Hege, in The Visualization Handbook; Amira: A Highly Interactive System for Visual Data Analysis, edited by C. D. Hansen and C. R. Johnson (Elsevier, 2005) Chap. 38, pp. 749-767, ISBN 978-0-12-387582-2]. We gratefully acknowledge ZIB Amira for providing us a license.

• Gregory J. Colten
• Donald C. Hane
• Albert Kim
• Lingyi Kong
• Stuart L. Shapiro
• Brian R. Taylor
• Francis J. Walsh
University of Illinois at Urbana-Champaign

 Initial Configuration Evolution of Magnetic Fields Poynting Flux Gravitational Waveforms