A Late-Time Flattening of Afterglow Light Curves
A Late-Time Flattening of Afterglow Light Curves
复制标题
余辉光曲线的后期平坦化
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
S. Yost
中科院分区：
文献类型：
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作者：
D. Frail;B. Metzger;E. Berger;S. Kulkarni;S. Yost
我们提出了一个样品的无线电余辉光变曲线与测量的衰减斜率，显示在后期的平坦化的证据相比，光学和X射线衰减指数。这种行为的最简单的起源是，斜率的变化是由于喷流流出过渡到亚相对论膨胀。这可以解释样品中部分但不是全部爆发的晚期射电光变曲线。我们研究了几种可能的修改标准火球模型，它可以扁平后期的光变曲线。激波微物理的变化，控制粒子加速，或能量注入到激波（径向或方位角）可以重现观察到的行为。区分这些不同的可能性将需要同时光学/无线电监测余辉在晚些时候。
We present a sample of radio afterglow light curves with measured decay slopes that show evidence of a flattening at late times compared to optical and X-ray decay indices. The simplest origin for this behavior is that the change in slope is due to a jetlike outflow making a transition to subrelativistic expansion. This can explain the late-time radio light curves for some but not all of the bursts in the sample. We investigate several possible modifications to the standard fireball model, which can flatten late-time light curves. Changes to the shock microphysics, which govern particle acceleration, or energy injection to the shock (either radially or azimuthally) can reproduce the observed behavior. Distinguishing between these different possibilities will require simultaneous optical/radio monitoring of afterglows at late times.