发表机构
California Institute of Technology; Walter Burke Institute for Theoretical Physics, California Institute of Technology（加州理工学院; 加州理工学院沃尔特·伯克理论物理研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
研究通过广义相对论磁流体动力学模拟，发现Tayler-Spruit发电机可重塑中子星并合遗迹的角动量分布，形成大质量富中子吸积盘与抛射物，影响其演化与多信使特征。
AI 中文摘要
磁场放大与角动量（AM）输运对双中子星并合遗迹的长期演化、寿命及电磁特征有关键塑造作用。磁旋转不稳定性可在中子星遗迹与吸积盘的外负剪切区运作，而正剪切、稳定分层的核心则可能受Tayler-Spruit发电机影响。我们开展了首个纳入未分辨Tayler-Spruit发电机的中子星并合遗迹全球、长期广义相对论中微子辐射磁流体动力学模拟，采用新的平均场发电机亚格子方案。从真实并合遗迹出发的轴对称模拟显示，Tayler-Spruit发电机主要活跃于遗迹核心的高纬度区域，产生的麦克斯韦应力在数百毫秒的自旋时标上重新分布角动量，大幅扁平化核心旋转轮廓，将外层遗迹的质量与角动量转移至吸积盘，形成更大质量、更延展、强磁化且低电子丰度的吸积盘，进而产生大量富中子抛射物。我们的结果表明，当前未建模的Tayler-Spruit发电机作用可定性改变长寿命中子星并合遗迹的旋转演化、坍缩可能性、吸积盘形成及多信使特征。
英文摘要
Magnetic-field amplification and angular momentum (AM) transport critically shape the secular evolution, lifetime, and electromagnetic signatures of binary neutron-star merger remnants. While the magnetorotational instability can operate in the outer negative-shear regions of the neutron-star remnant and accretion disk, the positive-shear, stably stratified core may instead be susceptible to the Tayler-Spruit dynamo. We present the first global, long-term general-relativistic neutrino-radiation magnetohydrodynamics simulations of a neutron-star merger remnant incorporating the unresolved Tayler-Spruit dynamo through a new mean-field dynamo subgrid prescription. Our axisymmetric simulations starting from a realistic merger remnant show that the Tayler-Spruit dynamo is primarily active in high-latitude regions of the remnant core. The resulting Maxwell stresses redistribute AM on a spin-down timescale of a few hundred milliseconds, substantially flattening the core rotation profile and transferring mass and AM from the outer remnant into the disk. This produces a more massive, extended, and strongly magnetized disk with a low electron fraction, leading to substantially more neutron-rich ejecta. Our results demonstrate that currently unmodelled Tayler-Spruit dynamo action can qualitatively alter the rotational evolution, collapse prospects, disk formation, and multi-messenger signatures of long-lived neutron-star merger remnants.
CommentsMatches the published version in ApJL
