论文标题
在有效的相对论平均场模型中磁化的中子星形地壳
Magnetised neutron star crust within effective relativistic mean-field model
论文作者
论文摘要
即使中子星形外壳的结晶性质在描述各种迷人的天体物理观测中起关键作用,但在存在巨大磁场的情况下,其显微镜结构尚未完全理解。在目前的工作中,我们研究了有效的相对论平均野外框架中中子星的地壳特性,在存在磁场强度$ \ sim 10^{17} $ g。我们通过使用最新的原子质量评估来最大程度地减少吉布斯自由能来计算外壳的平衡组成。磁场显着影响状态方程(EOS)和外壳的特性,例如中子滴水密度,压力和熔化温度。对于内部地壳,我们首次使用可压缩的液滴模型来研究磁性环境中的地壳特性。内部外壳特性,例如质量和电荷数分布,等音不对称,簇密度等,显示出对磁场强度敏感的典型量子振荡(de haas-van alphen效应)。密度依赖性的对称能像无野外情况一样影响磁性内皮。我们研究了面食结构的可能修饰,并且观察到它们的质量和厚度会根据磁场强度而变化$ \ sim 10-15 \%$。在软伽玛中继器中,研究了磁化地壳(QPO)的基本扭转振荡模式频率。这项工作中考虑的磁场强度仅影响内壳外壳的外部和浅区域的EOS,从而导致全球中子星形性质没有显着变化。但是,随着磁场强度的增加,外壳质量及其惯性矩大大增加。
Even though the crystallize nature of the neutron star crust plays a pivotal role in describing various fascinating astrophysical observations, its microscopic structure is not fully understood in the presence of a colossal magnetic field. In the present work, we study the crustal properties of a neutron star within an effective relativistic mean field framework in the presence of magnetic field strength $\sim 10^{17}$G. We calculate the equilibrium composition of the outer crust by minimizing the Gibbs free energy using the most recent atomic mass evaluations. The magnetic field significantly affects the equation of state (EoS) and the properties of the outer crust, such as neutron drip density, pressure, and melting temperature. For the inner crust, we use the compressible liquid drop model for the first time to study the crustal properties in a magnetic environment. The inner crust properties, such as mass and charge number distribution, isospin asymmetry, cluster density, etc., show typical quantum oscillations (De Haas-van Alphen effect) sensitive to the magnetic field's strength. The density-dependent symmetry energy influences the magnetic inner crust like the field-free case. We study the probable modifications in the pasta structures and it is observed that their mass and thickness changes by $\sim 10-15 \%$ depending upon the magnetic field strength. The fundamental torsional oscillation mode frequency is investigated for the magnetized crust in the context of quasiperiodic oscillations (QPO) in soft gamma repeaters. The magnetic field strengths considered in this work influences only the EoS of outer and shallow regions of the inner crust, which results in no significant change in global neutron star properties. However, the outer crust mass and its moment of inertia increase considerably with increase in magnetic field strength.