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HK: Fachverband Physik der Hadronen und Kerne

HK 49: Nuclear Astrophysics IV

HK 49.4: Vortrag

Mittwoch, 13. März 2024, 18:30–18:45, HBR 14: HS 4

Neutron-star merger models including all phases of matter ejection — •Oliver Just^1,2, Vimal Vijayan^1,3, Zewei Xiong¹, Stephane Goriely⁴, Theodoros Soultanis¹, Andreas Bauswein^1,5, Jerome Guilet⁶, Hans-Thomas Janka⁷, and Gabriel Martinez-Pinedo^1,5,8 — ¹GSI, Darmstadt, German — ²RIKEN, Saitama, Japan — ³Ruprecht-Karls-Universität, Heidelberg, Germany — ⁴ULB, Brussels, Belgium — ⁵FAIR HFHF, Darmstadt, Germany — ⁶Paris University, France — ⁷MPA, Garching, Germany — ⁸IKP, Darmstadt, Germany

Collisions of two neutron stars, as first observed in 2017, are unique nuclear physics laboratories. The material ejected during these events is believed to undergo the rapid neutron-capture (r-) process, and the nuclear equation of state (EOS) has a crucial impact on the lifetime of the hyper-massive merger remnant until it collapses to a black hole. In order to predict the observational signature, e.g. the kilonova signal, of r-process nucleosynthesis and the nuclear EOS, detailed numerical simulations are necessary, ideally covering all phases of matter ejection. Most existing simulations, however, focus only on the first tens of milliseconds and neglect the subsequent ("post-merger") evolution. This contribution presents our recent study where we developed models of delayed-collapse mergers, which cover about 100 seconds, i.e. all relevant phases of matter ejection. Such "end-to-end" models are essential for reliably predicting the total r-process yields, the geometric distribution of different chemical elements in the ejecta, and for assessing the impact of the remnant lifetime on the kilonova.

Keywords: r-process nucleosynthesis; neutron-star mergers; kilonova; neutron star; numerical simulation