Speaker
Description
Binary neutron star (BNS) systems are currently understood as prominent sources of heavy elements and electromagnetic signatures originating from nucleosynthetic processes. These processes are highly sensitive to the thermodynamical state of the ejected material. To model such complex systems, numerical relativity has emerged as a suitable framework, which provides the means to assess information about the matter outflows. Due to the importance of weak interaction processes for setting the thermal and compositional state of the ejecta, BNS simulations should include neutrinos by, for example, the commonly employed two moments (M1) scheme with integrated (grey approximation) neutrino fields. Interaction rates then determine the feedback between neutrinos and matter, which can be computed with varied degrees of sophistication. In this work, we present BNS merger simulations with M1 neutrino transport, aiming to quantify the role of the neutrinos' interaction rates on the predicted properties of the ejecta, disk and remnant. For that, we adopt three prescriptions for beta reactions: the simplest elastic approximation, the more complete rates provided by the NuLib library, and a full kinematics treatment. Finally, we show that the improved microscopical treatment of the neutrino rates produces significant differences in our simulations, possibly impacting observational signatures from such events.