Neutron star collisions could briefly trap a bunch of cosmic ghosts

When it comes to "busting" cosmic ghosts, only the most extreme objects in the universe may be up to the task: neutron stars.

Scientists have performed simulations of collisions between these ultradense and dead stars, showing that such powerful events may be able to briefly "trap" neutrinos, otherwise known as "ghost particles." The discovery could help scientists better understand neutron star mergers as a whole, which are events that create environments turbulent enough to forge elements heavier than iron. Such elements can't even be created at the hearts of stars — and this includes the gold on your finger and the silver around your neck.

Neutrinos are considered to be the "ghosts" of the particle zoo due to their lack of charge and incredibly small mass. These characteristics mean they very rarely interact with matter. To put that into perspective, as you read this sentence, more than 100 trillion neutrinos are streaming through your body at near-light speed, and you can't feel a thing.

These new simulations of neutron star mergers were performed by Penn State University physicists, and ultimately showed that the point at which these dead stars meet (the interface) becomes incredibly hot and dense. In fact, it becomes extreme enough to ensnare a bunch of those "cosmic ghosts."

At least for a short time, anyway.

Despite their lack of interaction with matter, neutrinos created in the collision would get trapped at that neutron-star-merger interface and become much hotter than the relatively cold hearts of the colliding dead stars.

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This is referred to as the neutrinos being "out of thermal equilibrium" with the cold neutron star cores. During this hot phase, which lasts around two to three milliseconds, the team's simulations indicated neutrinos can interact with merging neutron star matter, in turn helping to reestablish thermal equilibrium.