Evaluation of heavy element nucleosynthesis in rotating proto-magnetar winds using tracer particles

Heavy element nucleosynthesis via the rapid neutron capture process (r-process) is responsible for producing roughly half of all elements heavier than iron in the Universe, but the astrophysical origin of the r-process elements has been a longstanding mystery. The hot and dense environment in the aftermath of supernova explosions has been suggested as one of the potential sources of these heavy elements. Successful explosion of massive stars is followed by a neutrino-driven wind cooling phase of newly born protoneutron stars (PNSs). Wind models that do not consider strong magnetic fields or rotation of the PNS fail to achieve the necessary conditions for production of the third r-process peak, but robustly produce a weak r-process in neutron-rich winds. Using 2D magnetohydrodynamic simulations with magnetar-strength magnetic fields and rotation, we show that high entropy material is quasi-periodically ejected from the closed zone of the PNS magnetosphere. We incorporate tracer particles into the wind simulations to track the physical and thermodynamic trajectories of fluid parcels in the wind. We post-process the tracer trajectories using the nuclear reaction network SkyNet to study the yield of various elements and find that magnetar winds can produce a robust r-process upto and beyond the third peak.