Spectral Properties of Prompt Emission of Four Short Gamma-Ray Bursts Observed by the Suzaku-WAM and the Konus-Wind
Spectral Properties of Prompt Emission of Four Short Gamma-Ray Bursts Observed by the Suzaku-WAM and the Konus-Wind
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DOI：
10.1093/pasj/60.sp1.s361
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发表时间：
2008-01
影响因子：
2.3
通讯作者：
M. Ohno;Y. Takahashi;K. Yamaoka;S. Sugita;V. Pal'shin;T. Sakamoto;G. Sato;K. Hurley;D. Frederiks
中科院分区：
文献类型：
--
作者：
M. Ohno;Y. Takahashi;K. Yamaoka;S. Sugita;V. Pal'shin;T. Sakamoto;G. Sato;K. Hurley;D. Frederiks
我们用Suzaku-WAM和Konus-Wind实验对四个明亮的短伽玛射线暴的瞬发辐射进行了联合分析。这种联合分析使我们能够在更宽的能带上以更高的精度研究短持续时间爆发的光谱特性。我们发现，这些爆发有一个高的E$_{\rm峰值}$，约1兆电子伏，并有一个更难的幂律分量比长的伽玛暴。然而，我们不能确定这些光谱是否遵循截止幂律模型或带模型。我们还研究了光谱滞后，硬度比，推断各向同性辐射能量和存在的软发射驼峰，为了将它们分为短或长的伽玛暴使用几个标准，除了爆发持续时间。我们发现，所有的标准，除了软驼峰的存在，支持的事实，我们的四个伽玛暴样品被正确地归类为属于短类。此外，我们的宽带分析表明，没有证据表明伽玛暴具有非常大的硬度比，如在BATSE短伽玛暴样品中所看到的，并且我们的四个短伽玛暴的光谱滞后与零一致，即使在MeV的能带中，与长伽玛暴不同。虽然我们的短伽玛暴样品仍然有限，这些结果表明，短伽玛暴的光谱硬度可能没有显着不同的长伽玛暴，也在高能量的光谱滞后可能是一个强有力的标准爆发分类。
We have performed a joint analysis of prompt emission from four bright short gamma-ray bursts (GRBs) with the Suzaku-WAM and the Konus-Wind experiments. This joint analysis allows us to investigate the spectral properties of short-duration bursts over a wider energy band with a higher accuracy. We find that these bursts have a high E$_{\rm peak}$, around 1 MeV and have a harder power-law component than that of long GRBs. However, we can not determine whether these spectra follow the cut-off power-law model or the Band model. We also investigated the spectral lag, hardness ratio, inferred isotropic radiation energy and existence of a soft emission hump, in order to classify them into short or long GRBs using several criteria, in addition to the burst duration. We find that all criteria, except for the existence of the soft hump, support the fact that our four GRB samples are correctly classified as belonging to the short class. In addition, our broad-band analysis revealed that there is no evidence of GRBs with a very large hardness ratio, as seen in the BATSE short GRB sample, and that the spectral lag of our four short GRBs is consistent with zero, even in the MeV energy band, unlike long GRBs. Although our short GRB samples are still limited, these results suggest that the spectral hardness of short GRBs might not differ significantly from that of long GRBs, and also that the spectral lag at high energies could be a strong criterion for burst classification.