Titol: Tracking dynamical matter in binary neutron star mergers for nucleosynthesis processes

Lloc: Seminari del DAA. Edifici Investigació Jeroni Muñoz, planta quarta, a Burjassot.

Dia: divendres 27 de juny de 2025. Hora: 12:00.

Resum:

The exact geometry of a neutron star’s magnetic field remains unknown, and differing magnetic field configurations may influence mass ejection from Binary Neutron Star (BNS) mergers. Dynamical ejecta from BNS mergers are promising sites for R-process nucleosynthesis, and since their dynamics influence thermodynamic conditions in the ejecta, different magnetic field geometries could impact any nucleosynthesis that occurs here. These effects are quantified by the final abundances resulting from the R-process under purely poloidal, toroidal and absent internal magnetic fields. To achieve this, 2 and 3-dimensional codes were constructed to generate, select and trace dynamical ejecta particles backwards in the post-processing of BNS merger simulation data produced by the IllinoisGRMHD code. Both codes produced trajectories consistent with expected behaviour for dynamical ejecta, reproducing paths characteristic of shock-heated and tidal ejecta. This allows tracers to be computed after the simulation has been created, facilitating the tracing of many more particles than typically possible. These paths were used to interpolate quantities such as temperature, electron fraction and mass-density along the trajectory, which can now be inputted into the WINNET network to simulate the nucleosynthesis in the dynamical ejecta under different NS magnetic field configurations.