LIMITS ON PROMPT, DISPERSED RADIO PULSES FROM GAMMA-RAY BURSTS
LIMITS ON PROMPT, DISPERSED RADIO PULSES FROM GAMMA-RAY BURSTS
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DOI：
10.1088/0004-637x/757/1/38
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发表时间：
2012-07
期刊：
影响因子：
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通讯作者：
K. Bannister;T. Murphy;B. Gaensler;J. Reynolds
中科院分区：
文献类型：
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作者：
K. Bannister;T. Murphy;B. Gaensler;J. Reynolds
我们利用12米望远镜在1.4 GHz频率上搜索了9个伽玛射线暴（GRBs）的快速射电发射，时间分辨率为64 μs至1 s。我们在两次grb之后的几分钟内检测到单个分散的射电脉冲，其显著性为bbb60 σ。两个脉冲的色散测量值都远远超过银河系的预期值，隐含的速率与已知的单分散脉冲源不相容。两个脉冲的到达时间也与伽马射线暴x射线光曲线的断裂时间一致。无效试验和统计论证分别以95%和97%的置信度排除了随机波动作为这些脉冲的起源，尽管简单的种群论证支持GRB起源的置信度仅为2%。我们警告说，我们不能排除射频干扰（RFI）作为这些脉冲的来源。如果单脉冲与GRB无关，我们将GRB后200 ~ 1800s发射的射电脉冲通量密度上限设定为1.27w−1/2 Jy，其中6.4 × 10−5 s 1 s)变化。在GRB现象的早期阶段，这些限制在高时间分辨率和千兆赫频率下是最具限制性的。
We have searched for prompt radio emission from nine gamma-ray bursts (GRBs) with a 12 m telescope at 1.4 GHz, with a time resolution of 64 μs to 1 s. We detected single dispersed radio pulses with significances >6σ in the few minutes following two GRBs. The dispersion measures of both pulses are well in excess of the expected Galactic values, and the implied rate is incompatible with known sources of single dispersed pulses. The arrival times of both pulses also coincide with breaks in the GRB X-ray light curves. A null trial and statistical arguments rule out random fluctuations as the origin of these pulses with >95% and ∼97% confidence, respectively, although a simple population argument supports a GRB origin with confidence of only 2%. We caution that we cannot rule out radio frequency interference (RFI) as the origin of these pulses. If the single pulses are not related to the GRBs, we set an upper limit on the flux density of radio pulses emitted between 200 and 1800 s after a GRB of 1.27w−1/2 Jy, where 6.4 × 10−5 s 1 s) variations. These limits are some of the most constraining at high time resolution and GHz frequencies in the early stages of the GRB phenomenon.