论文标题
用3D的磁性积聚流对GRB喷气性能进行建模
Modeling the GRB jet properties with 3D general relativistic simulations of magnetically arrested accretion flows
论文作者
论文摘要
我们研究了GRB射流结构的依赖性及其对中央发动机积聚圆环的性质的演变。我们的模型使用3D一般相对论的磁性水动力模拟在数值上进化了Kerr黑洞周围的吸积盘。我们根据鱼骨刺激和Chakrabarti溶液使用两个不同的积聚磁盘的分析流体动力学模型，作为我们的初始状态，分别是折叠盘的结构，分别是二进制中子星星合并后的残余。我们在初始稳定溶液上施加了两个不同几何形状的多磁场。我们研究了磁滞留的磁盘状态的形成和演变及其对发射喷气机构的影响。我们的模型中产生的喷气机是结构化的，具有相对空心的核心，并以一定角度$ \ gtrsim 9 {^\ circ} $从轴上达到更高的洛伦兹因子。我们短的GRB型号中的喷气机的开头角度最高为$ \ sim 25^{\ circ} $，而我们的长GRB发动机则产生较窄的喷气机，最高为$ \ sim 11^{\ circ} $。我们还研究了喷气机的时间变异性，并提供了模型中最小变异时间尺度的估计。简要讨论了我们的模型在二进制中子星后系统中的GRB喷气机中以及从倒塌星星发射的超偏见的喷气机中的应用。
We investigate the dependence of the GRB jet structure and its evolution on the properties of the accreting torus in the central engine. Our models numerically evolve the accretion disk around a Kerr black hole using 3D general relativistic magnetohydrodynamic simulations. We use two different analytical hydrodynamical models of the accretion disk, based on the Fishbone-Moncrief and Chakrabarti solutions, as our initial states for the structure of the collapsar disk and the remnant after a binary neutron star merger, respectively. We impose poloidal magnetic fields of two different geometries upon the initial stable solutions. We study the formation and evolution of the magnetically arrested disk state and its effect on the properties of the emitted jet. The jets produced in our models are structured and have a relatively hollow core and reach higher Lorentz factors at an angle $\gtrsim 9{^\circ}$ from the axis. The jet in our short GRB model has an opening angle of up to $\sim 25^{\circ}$ while our long GRB engine produces a narrower jet, of up to $\sim 11^{\circ}$. We also study the time variability of the jets and provide an estimate of the minimum variability timescale in our models. The application of our models to the GRB jets in the binary neutron star post-merger system and to the ultra-relativistic jets launched from collapsing stars are briefly discussed.
