Dependence of the spectral evolution of γ-ray bursts on their photon fluence
Dependence of the spectral evolution of γ-ray bursts on their photon fluence
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DOI：
10.1038/381049a0
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发表时间：
1996-05
期刊：
影响因子：
64.8
通讯作者：
E. Liang;V. Kargatis
中科院分区：
文献类型：
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作者：
E. Liang;V. Kargatis
γ射线暴的本质仍然是现代天文学的一大谜团。虽然这些高能量源的空间分布受到严格的限制（它们在天空中各向同性分布3），但它们的光谱和时间特性却不能这么说，因为几乎没有明确的趋势被确定1，2。但是，正是从这些性质中，很可能得到关于爆发背后的物理机制的重要线索4，5。在这里，我们表明，对于由分辨率良好、隔离的能量脉冲组成的爆发样本，并且其光谱足够干净，可以对其时间演化进行建模，每个脉冲功率输出最大时的光子能量随着光子注量（即，光子通量的运行时间积分）呈指数下降。我们发现，对于许多多脉冲爆发，指数衰减常数从脉冲到脉冲是不变的。这种性质有利于脉冲产生于再生源的模型，而不是单一灾难性事件的结果。
THE nature of γ-ray bursts remains one of the great mysteries of modern astronomy1,2. Although the spatial distribution of these high-energy sources is tightly constrained (they are distributed isotropically across the sky3), the same cannot be said of their spectral and temporal properties, for which few clear trends have been identified1,2. But it is from such properties that important clues about the physical mechanisms underlying the bursts are likely to be derived4,5. Here we show that for a sample of bursts consisting of well resolved, isolated energy pulses, and for which the spectra are sufficiently clean to allow their temporal evolution to be modelled, the photon energy at which the power output is maximum for each pulse decreases exponentially with photon fluence (that is, running time integral of photon flux). We find that for many multi-pulse bursts, the exponential decay constant is invariant from pulse to pulse. This property favours models in which the pulses arise from a regenerative source, rather than as a consequence of a single catastrophic event.