The evolution of tidal streams in the aftermath of white dwarf mergers

In this work, a series of Smoothed Particle Hydrodynamics simulations of the coalescence between two He and CO white dwarfs is presented. The simulations discussed here encompass a wide range of stellar masses that are representative of the Galactic white dwarf field population. Both the chemical and the hydrodynamical evolution of the mergers simulated here have been analyzed in detail. This has allowed us to characterize possible different outcomes for the merger and to calculate its potential observational signatures, such as the associated gravitational waveforms, the expected number of neutrinos emitted, the fallback luminosities, and the emitted light curves. Special attention has been paid to the formation and evolution of the tidal stream formed during the process of disruption of the secondary white dwarf. Unlike any previous study in the subject, we have been found that the tidal stream is fragmented. Its potential consequences have been explored and possible different explanations for this have been considered.