2020/07/31 by S. K. Lander, P. Haensel, B. Haskell +2
Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics #Equation of state #Field strength #Gamma-ray bursts and supernovae #Geometry #Magnetic field #Neutron star #Nuclear physics #Physics #Plasma #Pulsars and Gravitational Waves Research #Quantum mechanics #Rotation (mathematics) #Stars #Stellar evolution #Stellar rotation #Stellar structure #Toroid #astro-ph.HE #astro-ph.SR
paper · pdf · doi:10.1093/mnras/stab460
21 pages, 16 figures. Matched version accepted for publication in MNRAS. Some rewritten discussion and one entropy-profile plot changed from v1; main results unaffected
arxiv created 2021/02/12 · openalex publication_date 2021/02/16 · arxiv updated 2021/02/24 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
ABSTRACT We explore the thermal and magnetic field structure of a late-stage proto-neutron star (proto-NS). We find the dominant contribution to the entropy in different regions of the star, from which we build a simplified equation of state (EOS) for the hot neutron star (NS). With this, we numerically solve the stellar equilibrium equations to find a range of models, including magnetic fields and rotation up to Keplerian velocity. We approximate the EOS as a barotrope, and discuss the validity of this assumption. For fixed magnetic field strength, the induced ellipticity increases with temperature; we give quantitative formulae for this. The Keplerian velocity is considerably lower for hotter stars, which may set a de facto maximum rotation rate for non-recycled NSs well below 1 kHz. Magnetic fields stronger than around 1014 G have qualitatively similar equilibrium states in both hot and cold NSs, with large-scale simple structure and the poloidal field component dominating over the toroidal one; we argue this result may be universal. We show that truncating magnetic field solutions at low multipoles leads to serious inaccuracies, especially for models with rapid rotation or a strong toroidal-field component.