Unraveling Neutron Star Mergers: Magnetic Fields and Gamma-Ray Bursts

Neutron star mergers are known to generate gamma-ray bursts, which are among the most energetic explosions in the universe. Prior to a merger, the stars rotate, producing intensely strong magnetic fields.

These fields can be up to 10 trillion times stronger than a typical refrigerator magnet.

Such powerful magnetic fields are capable of converting gamma-rays directly into electrons and positrons, and rapidly accelerating these particles to high energies.

Simulations Uncover Pre-Merger Dynamics

Scientists utilized NASA’s Pleiades supercomputer to conduct over 100 simulations. The objective was to observe how varying magnetic field configurations influenced the emission of electromagnetic waves from a system of two orbiting neutron stars, each with 1.4 solar masses.

Most of these simulations focused on the 7.7 milliseconds immediately preceding a merger.

The results indicated a significant interaction of magnetic field lines during this interval, characterized by processes of connection, breakage, and reconnection. Throughout these field interactions, particles are transformed into radiation, and radiation into particles.

Energetic Emissions and Future Detection

The simulations also identified specific regions where the most energetic gamma-rays originate. These high-energy rays are unable to escape the system as they quickly convert into particles due to the strong magnetic fields present. However, gamma-rays at lower energy levels can exit the merging system and potentially lead to the production of X-rays.

Future observational facilities may be able to detect these lower-energy emissions, providing insights into neutron star mergers just before they occur.