FERMI-LAT DETECTION OF PULSED GAMMA-RAYS ABOVE 50 GeV FROM THE VELA PULSAR
FERMI-LAT DETECTION OF PULSED GAMMA-RAYS ABOVE 50 GeV FROM THE VELA PULSAR
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DOI：
10.1088/2041-8205/797/2/l13
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发表时间：
2014-10
期刊：
影响因子：
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通讯作者：
G. Leung;J. Takata;C. Ng;A. Kong;P. Tam;C. Hui;K. Cheng
中科院分区：
文献类型：
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作者：
G. Leung;J. Takata;C. Ng;A. Kong;P. Tam;C. Hui;K. Cheng
第一个费米-大区域望远镜（LAT）的10 GeV以上的源目录报告了12颗恒星超过25 GeV的脉冲发射的证据，其中包括船帆座脉冲星，它显示了超过37 GeV能带的脉冲。使用62个月的费米-LAT数据，我们分析了船帆座脉冲星的伽马射线发射，并寻找50 GeV以上的脉冲发射。在用H检验确认了30-50 GeV脉冲的显著性（p值为10−77）之后，我们使用贝叶斯块算法提取了它的脉冲轮廓，并使用似然比检验将其与5个观测到的50 GeV以上光子的分布进行了比较。当光子能量超过50 GeV时，会发现明显的脉动现象，p值=3 × 10−5（4.2σ）。脉动的检测在>79 GeV的能量带高于4σ和>90 GeV的能量带高于3σ是显著的，使得这是LAT显著检测到的最高能量脉动。我们探讨了船帆座脉冲星甚高能量辐射的非定常外隙情形。
The first Fermi-Large Area Telescope (LAT) catalog of sources above 10 GeV reported evidence of pulsed emission above 25 GeV from 12 pulsars, including the Vela pulsar, which showed evidence of pulsation at >37 GeV energy bands. Using 62 months of Fermi-LAT data, we analyzed the gamma-ray emission from the Vela pulsar and searched for pulsed emission above 50 GeV. Having confirmed the significance of the pulsation in 30–50 GeV with the H test (p-value ∼10−77), we extracted its pulse profile using the Bayesian block algorithm and compared it with the distribution of the five observed photons above 50 GeV using the likelihood ratio test. Pulsation was significantly detected for photons above 50 GeV with a p-value of =3 × 10−5 (4.2σ). The detection of pulsation is significant above 4σ at >79 GeV and above 3σ at >90 GeV energy bands, making this the highest energy pulsation significantly detected by the LAT. We explore the non-stationary outer gap scenario of the very high-energy emissions from the Vela pulsar.