Speaker
Description
While the external magnetic fields of neutron stars are inferred through electromagnetic observations, the structure and strength of their internal fields remain largely unconstrained. The persistence of strong magnetic fields even in old neutron stars requires that their interior magnetic configuration must remain stable over astrophysical timescales. However, a fully consistent theoretical description of such stable equilibria has yet to be established. It is well known that purely poloidal and purely toroidal magnetic field configurations are unstable on dynamical timescales, while mixed-fields can be secularly stable under certain conditions. In this talk, I will revisit a semi-analytical framework originally developed by former members of Prof. Kokkotas’ group and collaborators. The main benefit of the scheme is that it combines the flexibility of analytical models with the ability to include realistic, microphysical ingredients related to stratification, amongst other things. I will show how, given some hydromagnetic equilibrium, (un)stable partitions can be identified as a function of equation-of-state particulars like the stratification set by composition gradients. I will highlight how these results apply to the magnetar population and their high-energy phenomena.