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Your search keyword '"Etienne, Zachariah B"' showing total 3 results
Start Over Author "Etienne, Zachariah B" Topic binary stars Topic neutron stars
3 results on '"Etienne, Zachariah B"'

2. General-relativistic simulations of binary black hole-neutron stars: Precursor electromagnetic signals.

Author

Paschalidis, Vasileios, Etienne, Zachariah B., and Shapiro, Stuart L.

Subjects
*RELATIVISTIC cosmology, *BINARY stars, *BINARY black holes, *NEUTRON stars, *SIMULATION methods & models, *MAGNETOSPHERE, *ELECTROMAGNETIC radiation
Abstract

We perform the first general relativistic force-free simulations of neutron star magnetospheres in orbit about spinning and nonspinning black holes. We find promising precursor electromagnetic emission: typical Poynting luminosities at, e.g., an orbital separation of r = 6.6/RNs are Lm ~ 6 X 1042(BNS,p/1013 G)²(MNS/1.4M⊙)² erg/s. The Poynting flux peaks within a broad beam of ~40° in the azimuthal direction and within ~60° 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. [ABSTRACT FROM AUTHOR]

Published
2013
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3. HARM3D+NUC: A New Method for Simulating the Post-merger Phase of Binary Neutron Star Mergers with GRMHD, Tabulated EOS, and Neutrino Leakage.

Author

Murguia-Berthier, Ariadna, Noble, Scott C., Roberts, Luke F., Ramirez-Ruiz, Enrico, Werneck, Leonardo R., Kolacki, Michael, Etienne, Zachariah B., Avara, Mark, Campanelli, Manuela, Ciolfi, Riccardo, Cipolletta, Federico, Drachler, Brendan, Ennoggi, Lorenzo, Faber, Joshua, Fiacco, Grace, Giacomazzo, Bruno, Gupte, Tanmayee, Ha, Trung, Kelly, Bernard J., and Krolik, Julian H.

Subjects
*STELLAR mergers, *NEUTRON stars, *BINARY stars, *RADIOACTIVE decay, *NEUTRINOS, *NUCLEAR astrophysics, *EQUATIONS of state, *GRAVITATIONAL waves
Abstract

The first binary neutron star merger has already been detected in gravitational waves. The signal was accompanied by an electromagnetic counterpart including a kilonova component powered by the decay of radioactive nuclei, as well as a short Îł -ray burst. In order to understand the radioactively powered signal, it is necessary to simulate the outflows and their nucleosynthesis from the post-merger disk. Simulating the disk and predicting the composition of the outflows requires general relativistic magnetohydrodynamical (GRMHD) simulations that include a realistic, finite-temperature equation of state (EOS) and self-consistently calculating the impact of neutrinos. In this work, we detail the implementation of a finite-temperature EOS and the treatment of neutrinos in the GRMHD code HARM3D+NUC, based on HARM3D. We include formal tests of both the finite-temperature EOS and the neutrino-leakage scheme. We further test the code by showing that, given conditions similar to those of published remnant disks following neutron star mergers, it reproduces both recombination of free nucleons to a neutron-rich composition and excitation of a thermal wind. [ABSTRACT FROM AUTHOR]

Published
2021
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