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  • The impact of r -process heating on the dynamics of neutron star merger accretion disc winds and their electromagnetic radiation
Title: The impact of r -process heating on the dynamics of neutron star merger accretion disc winds and their electromagnetic radiation
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.  more » « less
Award ID(s):
1815304
PAR ID:
10361432
Author(s) / Creator(s):
; ; ; ; ;
Publisher / Repository:
Oxford University Press
Date Published:
Journal Name:
Monthly Notices of the Royal Astronomical Society
Volume:
510
Issue:
2
ISSN:
0035-8711
Page Range / eLocation ID:
p. 2968-2979
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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