White dwarfs are the remnants of low to medium-mass stars that have burned their fuel. In binary systems, two white dwarfs can orbit each other and, under the right conditions, merge to form a more massive white dwarf. If this merged white dwarf exceeds a critical mass, it will undergo a thermonuclear explosion known as a Type Ia supernova.
Type Ia supernovae play an important role in many areas of astrophysics, from understanding the chemical evolution of the Universe to measuring distances to galaxies. However, the exact details of how white dwarfs merge and explode are still not fully understood.
To gain more insights into this process, the research team performed a series of simulations using the smoothed particle hydrodynamics (SPH) code, Nyx, developed by the University of Leicester. The researchers simulated different initial conditions, including the masses of the white dwarfs, their initial separation, and their rotation rates.
They found that the most common outcome of the merger is a thermonuclear explosion if the total mass of the system is above a critical limit, which is dependent on the equation of state used. The simulations also showed that the rotation of the white dwarfs can significantly affect the outcome of the merger, leading to the formation of a black hole instead of a supernova if the rotation is very rapid.
These simulations provide valuable information for understanding the conditions necessary for Type Ia supernovae to occur. In addition, the researchers are planning follow-up simulations to investigate other aspects of the binary white dwarf merger process, including the role of magnetic fields and the impact of additional physical effects, such as neutrino emission, to fully understand these powerful events.
