Magnetar formation through a convective dynamo in protoneutron stars

Understand

The release of spin-down energy by a magnetar is a promising scenario to power several classes of extreme explosive transients.

• However, it lacks a firm basis because magnetar formation still represents a theoretical challenge.
• Using the first three-dimensional simulations of a convective dynamo based on a protoneutron star interior model, we demonstrate that the required dipolar magnetic field can be consistently generated for sufficiently fast rotation rates.
• The dynamo instability saturates in the magnetostrophic regime with the magnetic energy exceeding the kinetic energy by a factor of up to 10.