Constraining Inputs to Realistic Kilonova Simulations through Comparison to Observed r-process Abundances

Marko Ristić; Erika M. Holmbeck; Ryan T. Wollaeger; Oleg Korobkin; Elizabeth Champion; Richard O’Shaughnessy; Chris L. Fryer; Christopher J. Fontes; Matthew R. Mumpower; Trevor M. Sprouse

doi:10.3847/1538-4357/acf3e0

The Astrophysical Journal (Jan 2023)

Constraining Inputs to Realistic Kilonova Simulations through Comparison to Observed r-process Abundances

Marko Ristić,
Erika M. Holmbeck,
Ryan T. Wollaeger,
Oleg Korobkin,
Elizabeth Champion,
Richard O’Shaughnessy,
Chris L. Fryer,
Christopher J. Fontes,
Matthew R. Mumpower,
Trevor M. Sprouse

Affiliations

Marko Ristić: ORCiD; Center for Computational Relativity and Gravitation, Rochester Institute of Technology , Rochester, NY 14623, USA
Erika M. Holmbeck: ORCiD; Observatories of the Carnegie Institution for Science , Pasadena, CA 91101, USA; Joint Institute for Nuclear Astrophysics—Center for the Evolution of the Elements , USA
Ryan T. Wollaeger: ORCiD; Center for Theoretical Astrophysics, Los Alamos National Laboratory , Los Alamos, NM 87545, USA; Computer, Computational, and Statistical Sciences Division, Los Alamos National Laboratory , Los Alamos, NM 87545, USA
Oleg Korobkin: ORCiD; Center for Theoretical Astrophysics, Los Alamos National Laboratory , Los Alamos, NM 87545, USA; Theoretical Division, Los Alamos National Laboratory , Los Alamos, NM 87545, USA
Elizabeth Champion: ORCiD; Department of Physics and Astronomy, University of Rochester , Rochester, NY 14627, USA
Richard O’Shaughnessy: ORCiD; Center for Computational Relativity and Gravitation, Rochester Institute of Technology , Rochester, NY 14623, USA
Chris L. Fryer: ORCiD; Center for Theoretical Astrophysics, 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
Christopher J. Fontes: ORCiD; Center for Theoretical Astrophysics, Los Alamos National Laboratory , Los Alamos, NM 87545, USA; Computational Physics Division, Los Alamos National Laboratory , Los Alamos, NM 87545, USA
Matthew R. Mumpower: ORCiD; Joint Institute for Nuclear Astrophysics—Center for the Evolution of the Elements , USA; Center for Theoretical Astrophysics, Los Alamos National Laboratory , Los Alamos, NM 87545, USA; Theoretical Division, Los Alamos National Laboratory , Los Alamos, NM 87545, USA
Trevor M. Sprouse: ORCiD; Joint Institute for Nuclear Astrophysics—Center for the Evolution of the Elements , USA; Center for Theoretical Astrophysics, Los Alamos National Laboratory , Los Alamos, NM 87545, USA; Theoretical Division, Los Alamos National Laboratory , Los Alamos, NM 87545, USA

DOI: https://doi.org/10.3847/1538-4357/acf3e0
Journal volume & issue: Vol. 956, no. 1
p. 64

Abstract

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Kilonovae, one source of electromagnetic emission associated with neutron star mergers, are powered by the decay of radioactive isotopes in the neutron-rich merger ejecta. Models for kilonova emission consistent with the electromagnetic counterpart to GW170817 predict characteristic abundance patterns, determined by the relative balance of different types of material in the outflow. Assuming that the observed source is prototypical, this inferred abundance pattern in turn must match r -process abundances deduced by other means, such as what is observed in the solar system. We report on analysis comparing the input mass-weighted elemental compositions adopted in our radiative transfer simulations to the mass fractions of elements in the Sun, as a practical prototype for the potentially universal abundance signature from neutron star mergers. We characterize the extent to which our parameter inference results depend on our assumed composition for the dynamical and wind ejecta and examine how the new results compare to previous work. We find that a dynamical ejecta composition calculated using the FRDM2012 nuclear mass and FRLDM fission models with extremely neutron-rich ejecta ( Y _e = 0.035) along with moderately neutron-rich ( Y _e = 0.27) wind ejecta composition yields a wind-to-dynamical mass ratio of M _w / M _d = 0.47, which best matches the observed AT2017gfo kilonova light curves while also producing the best-matching abundance of neutron capture elements in the solar system, though, allowing for systematics, the ratio may be as high as of order unity.

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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