The impact of r-process heating on the dynamics of neutron star merger accretion disc winds and their electromagnetic radiation

Hannah Klion, Alexander Tchekhovskoy, Daniel Kasen, Adithan Kathirgamaraju, Eliot Quataert, Rodrigo Fernández

Research output: Contribution to journalArticlepeer-review

1 Scopus citations

Abstract

Neutron star merger accretion discs can launch neutron-rich winds of >10-2M⊙. This ejecta is a prime site for r-process nucleosynthesis, which will produce a range of radioactive heavy nuclei. The decay of these nuclei releases enough energy to accelerate portions of the wind by ∼0.1c. Here, we investigate the effect of r-process heating on the dynamical evolution of disc winds. We extract the wind from a 3D general relativistic magnetohydrodynamic simulation of a disc from a post-merger system. This is used to create inner boundary conditions for 2D hydrodynamic simulations that continue the original 3D simulation. We perform two such simulations: one that includes the r-process heating, and another one that does not. We follow the hydrodynamic simulations until the winds reach homology (60 s). Using time-dependent multifrequency multidimensional Monte Carlo radiation transport simulations, we then calculate the kilonova light curves from the winds with and without dynamical r-process heating. We find that the r-process heating can substantially alter the velocity distribution of the wind, shifting the mass-weighted median velocity from 0.06c to 0.12c. The inclusion of the dynamical r-process heating makes the light curve brighter and bluer at $\sim 1\, \mathrm{d}$ post-merger. However, the high-velocity tail of the ejecta distribution and the early ($\lesssim 1\, \mathrm{d}$) light curves are largely unaffected.

Original languageEnglish (US)
Pages (from-to)2968-2979
Number of pages12
JournalMonthly Notices of the Royal Astronomical Society
Volume510
Issue number2
DOIs
StatePublished - Feb 2022

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Keywords

  • neutron star mergers
  • radiative transfer

Fingerprint

Dive into the research topics of 'The impact of r-process heating on the dynamics of neutron star merger accretion disc winds and their electromagnetic radiation'. Together they form a unique fingerprint.

Cite this