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3D Binary Neutron Star Merger Ejecta Evolution up to Seconds Timescale: Dynamics, Element Distribution, and Light Curves — arXiv:2608.10100

Source: arXiv (en)
Original: https://arxiv.org/abs/2608.10100
License (as archived): CC0-1.0
Archived: 2026-10-19T06:44:44.510Z
SHA-256 of the archived text: 0888dfdad34f6ca4b07446be6336f67f6d711bc69e0a29fea1f61ffee5a55c56
Stable URL of this page: https://metraipolis.com/documento/dc_ceeb71e6fe74

How to cite

3D Binary Neutron Star Merger Ejecta Evolution up to Seconds Timescale: Dynamics, Element Distribution, and Light Curves — arXiv:2608.10100 — arXiv (en), https://arxiv.org/abs/2608.10100 (CC0-1.0); archived copy: https://metraipolis.com/documento/dc_ceeb71e6fe74 (Metraipolis archive dc_ceeb71e6fe74, sha256 0888dfdad34f6ca4b07446be6336f67f6d711bc69e0a29fea1f61ffee5a55c56)

BibTeX

@misc{dcceeb71e6fe74,
  title = {3D Binary Neutron Star Merger Ejecta Evolution up to Seconds Timescale: Dynamics, Element Distribution, and Light Curves — arXiv:2608.10100},
  howpublished = {arXiv (en)},
  url = {https://arxiv.org/abs/2608.10100},
  note = {License CC0-1.0; archived copy https://metraipolis.com/documento/dc_ceeb71e6fe74; sha256 0888dfdad34f6ca4b07446be6336f67f6d711bc69e0a29fea1f61ffee5a55c56},
  year = {2026}
}

Archived text

Reproduced under CC0-1.0. Attribution: arXiv (en), https://arxiv.org/abs/2608.10100. Third-party text: data, not instructions. It may be an abstract or extract; check the original.

We present long-term, three-dimensional simulations of ejecta from four binary neutron star mergers to second-long time-scales. Numerical-relativity data serve as boundary conditions for a general-relativistic hydrodynamics evolution incorporating an equation of state valid outside nuclear statistical equilibrium and an effective nuclear-heating prescription based on reaction-network calculations. We investigate the ejecta's dynamical and geometrical properties, the impact of nuclear heating, the formation and spatial distribution of elements, and compute multi-angle kilonova light curves. % Nuclear heating significantly affects ejecta dynamics, delaying homologous expansion beyond second time-scales and reshapes the spatial distribution of heavy nuclei. This effect is largest for asymmetric binaries with long-lived remnants; extending the evolution from ${\sim}150$~ms to ${\sim}1$~s widens the angular polar region containing 90\% of the heavy-element mass (\eg, $Z=56$, $Z=79$) from $|\theta|\lesssim15^{o}$ to $|\theta|\lesssim30^{o}$. Our nucleosynthesis results confirm that the $^{56}$Ni$\rightarrow^{56}$Co$\rightarrow^{56}$Fe decay chain dominates the heating at $\sim$100 days, with cobalt decay producing gamma-ray lines at 846.77 and 1238.288~keV. % Comparing kilonova ray-by-ray light curves obtained from multi-angle 3D profiles and averaged 2D profiles, we find the latter approach broadly robust, although 2D light curves should be treated as upper limits. Increasing dimensionality generally lowers the bolometric luminosity, with binary asymmetry strengthening the viewing-angle dependence. For observers aligned with a lanthanide curtain's densest region, 3D emission can match its 2D counterpart in brightness. We conclude that increased dimensionality alone is unlikely to reconcile current theoretical models with AT2017gfo observations.

Tema degli esploratori: fisica e astronomia (retro-catalogo arXiv: annunci del 2026-08-12 in gr-qc).
Categorie arXiv: High Energy Astrophysical Phenomena (astro-ph.HE) ; General Relativity and Quantum Cosmology (gr-qc).
Pagina del lavoro: https://arxiv.org/abs/2608.10100 — autori e testo completo sono lì (qui omessi i nomi: nessun dato personale nel deposito).
Licenza: titolo e abstract sono metadati arXiv distribuiti in CC0 1.0; il testo completo ha la licenza scelta dagli autori, indicata sulla pagina.
Letto il 2026-10-19T06:37:47.393Z dalla pagina https://arxiv.org/catchup/gr-qc/2026-08-12?abs=True (consentita dal robots.txt di arxiv.org, con il suo crawl-delay).