SYNTHETIC OFF-AXIS LIGHT CURVES FOR LOW-ENERGY GAMMA-RAY BURSTS
SYNTHETIC OFF-AXIS LIGHT CURVES FOR LOW-ENERGY GAMMA-RAY BURSTS
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DOI：
10.1088/2041-8205/733/2/l37
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发表时间：
2011-02
期刊：
影响因子：
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通讯作者：
H. van Eerten;A. MacFadyen
中科院分区：
文献类型：
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作者：
H. van Eerten;A. MacFadyen
我们提出了大量的伽玛射线暴（GRB）余辉光变曲线计算的结果，通过结合高分辨率的二维相对论流体力学模拟使用RAM与同步辐射代码。结果得到射流能量，环爆介质密度，射流角度典型的短和underluminous GRBs，不同的观测角度，和观测频率从低无线电（75 MHz）的X射线（1.5千电子伏）。我们总结了光变曲线，通过光滑的幂律拟合与多达三个休息，涵盖小的观察者角度的射流休息，大的观察者角度的上升阶段，和反喷的上升和衰减。所有的光变曲线数据都可以在网上公开获得。这些数据可以用于模型拟合观测数据，并作为预测未来望远镜（如LOFAR或平方公里阵列）观测结果的辅助工具，并将有利于使用不同通道（如LIGO或Virgo的引力波观测）研究中子星星合并。对于小的观察者角度，我们发现喷流中断时间在频率之间变化很大，无线电中的中断时间大大推迟。增加观察者角度也推迟了测量的射流中断时间。对于大的观察者角度，光变曲线的上升阶段具有复杂的形状，不能总是用简单的幂律来概括。除了观察者角度很大的情况外，反喷流是光变曲线上的一个明显特征，尽管实际上那时的信号将非常难以观察。
We present results for a large number of gamma-ray burst (GRB) afterglow light curve calculations, done by combining high-resolution two-dimensional relativistic hydrodynamics simulations using ram with a synchrotron radiation code. Results were obtained for jet energies, circumburst medium densities, and jet angles typical for short and underluminous GRBs, different observer angles, and observer frequencies from low radio (75 MHz) to X-ray (1.5 keV). We summarize the light curves through smooth power-law fits with up to three breaks, covering jet breaks for small observer angles, the rising phase for large observer angles, and the rise and decay of the counterjet. All light curve data are publicly available on the Web. The data can be used for model fits to observational data and as an aid for predicting observations by future telescopes such as LOFAR or the Square Kilometer Array and will benefit the study of neutron star mergers using different channels, such as gravitational-wave observations with LIGO or Virgo. For small observer angles, we find jet break times that vary significantly between frequencies, with the break time in the radio substantially postponed. Increasing the observer angle also postpones the measured jet break time. The rising phase of the light curve for large observer angle has a complex shape that cannot always be summarized by a simple power law. Except for very large observer angles, the counterjet is a distinct feature in the light curve, although in practice the signal will be exceedingly difficult to observe by then.