A Broad Grid of 2D Kilonova Emission Models

• Published in: The Astrophysical journal Vol. 918; no. 1; pp. 10 - 26
• Main Authors: Wollaeger, R. T., Fryer, C. L., Chase, E. A., Fontes, C. J., Ristic, M., Hungerford, A. L., Korobkin, O., O’Shaughnessy, R., Herring, A. M.
• Format: Journal Article
• Language: English
• Published: Philadelphia The American Astronomical Society 01-09-2021; IOP Publishing
• Subjects: ASTRONOMY AND ASTROPHYSICS; Astrophysics; Composition; Ejecta; Emission; Infrared sources; Kilonovae; Light curve; Morphology; Neutron stars; R-proccess; R-process; Radiative transfer; Radiative transfer simulations; Simulation; Stellar evolution; Transient sources; Two dimensional models
• ISSN: 0004-637X; 1538-4357
• DOI: 10.3847/1538-4357/ac0d03

Abstract
Depending upon the properties of their compact remnants and the physics included in the models, simulations of neutron star mergers can produce a broad range of ejecta properties. The characteristics of this ejecta, in turn, define the kilonova emission. To explore the effect of ejecta properties, we present a grid of two-component 2D axisymmetric kilonova simulations that vary mass, velocity, morphology, and composition. The masses and velocities of each component vary, respectively, from 0.001 to 0.1
M
⊙
and 0.05 to 0.3
c
, covering much of the range of results from the neutron star merger literature. The set of 900 models is constrained to have a toroidal low electron fraction (
Y
e
) ejecta with a robust
r
-process composition and either a spherical or lobed high-
Y
e
ejecta with two possible compositions. We simulate these models with the Monte Carlo radiative transfer code
SuperNu
using a full suite of lanthanide and fourth-row element opacities. We examine the trends of these models with parameter variation, show how they can be used with statistical tools, and compare the model light curves and spectra to those of AT2017gfo, the electromagnetic counterpart of GW170817.