Simulating gamma-ray binaries with a relativistic extension of RAMSES
Simulating gamma-ray binaries with a relativistic extension of RAMSES
复制标题
使用 RAMSES 的相对论扩展模拟伽马射线双星
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
R. Teyssier
中科院分区：
文献类型：
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作者：
A. Lamberts;S. Fromang;G. Dubus;R. Teyssier
上下文伽马射线双星由一颗大质量星星和一颗具有高度相对论风的旋转动力脉冲星组成。来自两个物体的风之间的碰撞产生了一个激波结构，粒子被加速，这导致了观察到的高能发射。我们希望了解脉冲星风的相对论性质对碰撞风区域的结构和稳定性的影响，并强调与大质量恒星碰撞风的差异。我们专注于结构如何演变的脉冲星风的洛伦兹因子的值的增加，记住，目前的模拟是无法达到预期的脉冲星风洛伦兹因子的数量级的值。我们使用高分辨率的数值模拟与相对论扩展的流体动力学代码RAMSES，我们已经开发。我们进行二维模拟，并专注于该地区接近的二进制，轨道运动可以忽略不计。我们模拟了不同的脉冲星风洛伦兹因子值，最大可达16。我们确定恒星风碰撞和伽马射线双星之间的解析标度关系。它们提供了接触不连续的位置。冲击波的位置强烈地依赖于洛伦兹因子。我们发现，相对论风比预期的非相对论模拟的基础上更准直。超过一定的距离，冲击流被加速到其初始速度，并遵循绝热膨胀。最后，我们提供了指导外推到更现实的值的脉冲星风的洛伦兹因子。我们将自适应网格加密程序RAMSES扩展到相对论流体力学。该代码适用于研究天体物理对象，如脉冲星风星云，伽马射线爆发或相对论喷流，并将成为RAMSES下一个公开版本的一部分。使用这个代码，我们进行了模拟的伽玛射线双星高达Γp = 16，并强调了目前的伽玛射线双星的流体动力学模型的限制和可能性。
Context. Gamma-ray binaries are composed of a massive star and a rotation-powered pulsar with a highly relativistic wind. The collision between the winds from both objects creates a shock structure where particles are accelerated, which results in the observed high-energy emission.Aims. We want to understand the impact of the relativistic nature of the pulsar wind on the structure and stability of the colliding wind region and highlight the differences with colliding winds from massive stars. We focus on how the structure evolves with increasing values of the Lorentz factor of the pulsar wind, keeping in mind that current simulations are unable to reach the expected values of pulsar wind Lorentz factors by orders of magnitude.Methods. We use high-resolution numerical simulations with a relativistic extension to the hydrodynamics code RAMSES we have developed. We perform two-dimensional simulations, and focus on the region close to the binary, where orbital motion can be neglected. We model different values of the Lorentz factor of the pulsar wind, up to 16.Results. We determine analytic scaling relations between stellar wind collisions and gamma-ray binaries. They provide the position of the contact discontinuity. The position of the shocks strongly depends on the Lorentz factor. We find that the relativistic wind is more collimated than expected based on non-relativistic simulations. Beyond a certain distance, the shocked flow is accelerated to its initial velocity and follows adiabatic expansion. Finally, we provide guidance for extrapolation towards more realistic values of the Lorentz factor of the pulsar wind.Conclusions. We extended the adaptive mesh refinement code RAMSES to relativistic hydrodynamics. This code is suited to studying astrophysical objects, such as pulsar wind nebulae, gamma-ray bursts, or relativistic jets, and will be part of the next public release of RAMSES. Using this code we performed simulations of gamma-ray binaries up to Γp = 16 and highlighted the limits and possibilities of current hydrodynamical models of gamma-ray binaries.
DOI：
10.1088/0067-0049/193/1/6
发表时间：
2011-01
期刊：
The Astrophysical Journal Supplement Series
影响因子：
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作者：
K. Beckwith;J. Stone
通讯作者：
K. Beckwith;J. Stone