Particle-in-cell Simulations of Mildly Relativistic Outflows in Kilonova Emissions

Mohira Rassel; Patrick Kilian; Vito Aberham; Felix Spanier; Nicole Lloyd-Ronning; Chris L. Fryer

doi:10.3847/1538-4357/acd76a

The Astrophysical Journal (Jan 2023)

Particle-in-cell Simulations of Mildly Relativistic Outflows in Kilonova Emissions

Mohira Rassel,
Patrick Kilian,
Vito Aberham,
Felix Spanier,
Nicole Lloyd-Ronning,
Chris L. Fryer

Affiliations

Mohira Rassel: ORCiD; Center for Theoretical Astrophysics, Los Alamos National Laboratory , Los Alamos, NM 87545, USA ; [email protected]; Center for Non Linear Studies, Los Alamos National Laboratory , Los Alamos, NM 87545, USA
Patrick Kilian: ORCiD; Center for Theoretical Astrophysics, Los Alamos National Laboratory , Los Alamos, NM 87545, USA ; [email protected]; Space Science Institute , 4765 Walnut Street, Suite B, Boulder, CO 80301, USA
Vito Aberham: ORCiD; Institut für Theoretische Astrophysik, Universität Heidelberg , D-69120 Heidelberg, Germany
Felix Spanier: ORCiD; Institut für Theoretische Astrophysik, Universität Heidelberg , D-69120 Heidelberg, Germany
Nicole Lloyd-Ronning: ORCiD; Computational Physics and Methods Group, Los Alamos National Laboratory , Los Alamos, NM 87545, USA; Department of Math, Engineering & Science, University of New Mexico , Los Alamos, NM 87545, USA
Chris L. Fryer: ORCiD; Center for Theoretical Astrophysics, Los Alamos National Laboratory , Los Alamos, NM 87545, USA ; [email protected]; Center for Non Linear Studies, Los Alamos National Laboratory , Los Alamos, NM 87545, USA; Computer, Computational, and Statistical Sciences Division, Los Alamos National Laboratory , Los Alamos, NM 87545, USA; The University of Arizona , Tucson, AZ 85721, USA; Department of Physics and Astronomy, The University of New Mexico , Albuquerque, NM 87131, USA; The George Washington University , Washington, DC 20052, USA

DOI: https://doi.org/10.3847/1538-4357/acd76a
Journal volume & issue: Vol. 952, no. 2
p. 165

Abstract

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The electromagnetic emission from neutron star mergers is comprised of multiple components. Synchrotron emission from the disk-powered jet and thermal emission from the merger ejecta (powered by a variety of sources) are among the most studied sources. The low masses and high velocities of the merger ejecta quickly develop conditions where emission from collisionless shocks becomes critical and synchrotron emission from the merger ejecta constitutes a third component to the observed signal. The aim of this project is to examine shock development, magnetic field generation, and particle acceleration in the case of mildly relativistic shocks, which are expected when the tidal ejecta of neutron star mergers drive a shock into the external medium. Using LANL’s vector particle-in-cell (VPIC) code, we have run simulations of such mildly relativistic, collisionless, weakly magnetized plasmas and computed the resultant magnetic fields and particle energy spectra. We show the effects of varying plasma conditions, as well as explore the validity of using different proton-to-electron mass ratios in VPIC. Our results have implications for observing late-time electromagnetic counterparts to gravitational wave detections of neutron star mergers.

Published in The Astrophysical Journal

ISSN: 1538-4357 (Online)
Publisher: IOP Publishing
Country of publisher: United Kingdom
LCC subjects: Science: Astronomy: Astrophysics
Website: https://iopscience.iop.org/journal/0004-637X

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