Infrared/optical – X-ray simultaneous observations of X-ray flares in GRB 071112C and GRB 080506
Infrared/optical – X-ray simultaneous observations of X-ray flares in GRB 071112C and GRB 080506
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DOI：
10.1051/0004-6361/201014272
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发表时间：
2010-06
影响因子：
6.5
通讯作者：
T. Uehara;M. Uemura;K. Kawabata;Y. Fukazawa;R. Yamazaki;A. Arai;M. Sasada;T. Ohsugi;T. Mizuno;H. Takahashi;H. Katagiri;T. Yamashita;M. Ohno;G. Sato;S. Sato;M. Kino
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作者：
T. Uehara;M. Uemura;K. Kawabata;Y. Fukazawa;R. Yamazaki;A. Arai;M. Sasada;T. Ohsugi;T. Mizuno;H. Takahashi;H. Katagiri;T. Yamashita;M. Ohno;G. Sato;S. Sato;M. Kino
目标。我们研究了在伽玛射线暴（GRBs）余辉的早期阶段偶尔观察到的短x射线耀斑的起源。方法。我们使用1.5 m卡纳塔望远镜在光学和近红外（NIR）波段观测到两个雨燕事件，GRB 071112C和GRB 080506。结合已发表的x射线和光学数据，我们分析了密集采样的早期余辉光曲线和nir - x射线范围内的光谱能量分布（SEDs）。结果。我们发现，在两个grb的正常衰变阶段，seds在光学和x射线波段之间断裂，而不管在grb宿主星系中校正星际消光的模型如何。在x射线耀斑中，GRB 071112C和080506的x射线通量分别增加了3倍和15倍，并且x射线光谱比正常衰变阶段的光谱变得坚硬。与x射线耀斑一起，光学-近红外范围未检测到显著变化。结论。这些结果表明，x射线耀斑与来自双组分射流的后期内部冲击或外部冲击有关。
Aims. We investigate the origin of short X-ray flares which are occasionally observed in early stages of afterglows of gamma-ray bursts (GRBs). Methods. We observed two Swift events, GRB 071112C and GRB 080506, before the start of X-ray flares in the optical and nearinfrared (NIR) bands with the 1.5-m Kanata telescope. In conjunction with published X-ray and optical data, we analyzed densely sampled light curves of the early afterglows and spectral energy distributions (SEDs) in the NIR-X-ray ranges. Results. Wefound that the SEDshad abreak between the optical and X-ray bands inthe normal decay phases of both GRBsregardless of the model for the correction of the interstellar extinction in host galaxies of GRBs. In the X-ray flares, X-ray flux increased by 3 and 15 times in the case of GRB 071112C and 080506, respectively, and the X-ray spectra became harder than those in the normal decay phases. No significant variation in the optical-NIR range was detected together with the X-ray flares. Conclusions. These results suggest that the X-ray flares were associated with either late internal shocks or external shocks from two-component jets.