The configuration of the magnetic field in the interior of a neutron star is mostly unknown from observations. Theoretical models of the interior magnetic field geometry tend to be oversimplified to avoid mathematical complexity and tend to be based on axisymmetric barotropic fluid systems. These static magnetic equilibrium configurations have been shown to be unstable on a short time scale against an infinitesimal perturbation. Given this instability, it is relevant to consider how more realistic neutron star physics affects the outcome. In particular, it makes sense to ask if elasticity, which provides an additional restoring force on the perturbations, may stabilise the system. It is well-known that the matter in the neutron star crust forms an ionic crystal. The interactions between the crystallized nuclei can generate shear stress against any applied strain. To incorporate the effect of the crust on the dynamical evolution of the perturbed equilibrium structure, we study the effect of elasticity on the instability of an axisymmetric magnetic star. In particular we determine the critical shear modulus required to prevent magnetic instability and consider the corresponding astrophysical consequences.
Relaxation of magnetically-confined mountains on accreting neutron stars through cross-field mass transport
School of Physics, University of Melbourne（墨尔本大学物理学院）；ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav), University of Melbourne（引力波发现卓越研究中心（OzGrav），墨尔本大学）；Escola de Artes, Ciências e Humanidades, Universidade de São Paulo（圣保罗大学艺术、科学与人文学院）
Modelling mountains on accreting magnetized neutron stars
Università di Pisa（比萨大学）；Scuola Normale Superiore（比萨高等师范学院）；Università di Milano（米兰大学）；INFN, Sezione di Milano（意大利国家核物理研究所，米兰分部）；INFN, Sezione di Pisa（意大利国家核物理研究所，比萨分部）；INFN, Sezione di Ferrara（意大利国家核物理研究所，费拉拉分部）；Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences（波兰科学院尼古拉·哥白尼天文学中心）
