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arXiv 0907.2526astro-ph.HE
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ARGO-YBJ实验观测到的2008年Mrk421的Gamma-Ray耀斑

Gamma-Ray Flares from Mrk421 in 2008 observed with the ARGO-YBJ experiment

G. Di Sciascio

摘要:

在2008年,耀变体Mrk 421进入了一个非常活跃的阶段,是天空中最明亮的TeV能量源之一,显示出强烈和频繁的耀斑。我们利用位于羊八井(4300 m a.s.l.,中国西藏中国)。观察到的信号不是恒定的,并且与X射线测量相关。在源的活跃期间,平均发射大约是蟹状星云水平的两倍,对于E $_γ$ >1 TeV,积分通量为(4.9 $\pm 2.0$)x 10 $^{-11}$光子cm $^{-2}$ s $^{-1}$。本文集中在2008年6月,Mrk421耀斑活动已被研究,从光学到100 MeV的伽马射线,只有部分高达TeV的能量,因为月光阻碍了切伦科夫望远镜的观察后,6月8日。我们的数据完成了这些观测,在6月11日至13日检测到强度约为7个蟹状单位的第二次耀斑,统计学显著性为4.2个标准差。观测到的通量与同步加速器自康普顿模型框架中的预测一致,其中耀斑是由射流中轻子的快速加速引起的。

英文摘要:

In 2008, the blazar Mrk421 entered in a very active phase and was one of the brightest sources in the sky at TeV energies, showing strong and frequent flaring. We searched for gamma-ray emission at energies E > 0.8 TeV during the whole 2008 with the ARGO-YBJ experiment, a full coverage air shower detector located at Yangbajing (4300 m a.s.l., Tibet, P.R. China). The observed signal is not constant and in correlation with X-ray measurements. The average emission, during the active period of the source, was about twice the Crab Nebula level, with an integral flux of (4.9$\pm 2.0$)x 10$^{-11}$ photons cm$^{-2}$ s$^{-1}$ for E$_γ$ >1 TeV. This paper concentrates on 2008 June when the Mrk421 flaring activity has been studied from optical to 100 MeV gamma rays, and only partially up to TeV energies, since the moonlight hampered the Cherenkov telescope observations after 8 June. Our data complete these observations, with the detection of a second flare of intensity of about 7 Crab units on June 11-13, with a statistical significance of 4.2 standard deviations. The observed flux is consistent with a prediction made in the framework of the Synchrotron Self-Compton model, in which the flare is caused by a rapid acceleration of leptons in the jet.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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