Magnetized Outflows from Short-lived Neutron Star Merger Remnants Can Produce a Blue Kilonova

• Published in: Astrophysical journal. Letters Vol. 961; no. 1; p. L26
• Main Authors: Curtis, Sanjana, Bosch, Pablo, Mösta, Philipp, Radice, David, Bernuzzi, Sebastiano, Perego, Albino, Haas, Roland, Schnetter, Erik
• Format: Journal Article
• Language: English
• Published: Austin The American Astronomical Society 01.01.2024; IOP Publishing; American Astronomical Society
• Subjects: Binary stars; Compact objects; Ejecta; Emission analysis; Kilonovae; Magnetohydrodynamic simulation; Neutrinos; Neutron stars; Nuclear fusion; Outflow; Star mergers; Stellar evolution; Transient sources
• ISSN: 2041-8205; 2041-8213
• DOI: 10.3847/2041-8213/ad0fe1

We present a 3D general-relativistic magnetohydrodynamic simulation of a short-lived neutron star remnant formed in the aftermath of a binary neutron star merger. The simulation uses an M1 neutrino transport scheme to track neutrino–matter interactions and is well suited to studying the resulting nucleosynthesis and kilonova emission. A magnetized wind is driven from the remnant and ejects neutron-rich material at a quasi-steady-state rate of 0.8 × 10 −1 M ⊙ s −1 . We find that the ejecta in our simulations underproduce r -process abundances beyond the second r -process peak. For sufficiently long-lived remnants, these outflows alone can produce blue kilonovae, including the blue kilonova component observed for AT2017gfo.