Search for the shortest variability at gamma rays in flat-spectrum radio quasars
Search for the shortest variability at gamma rays in flat-spectrum radio quasars
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DOI：
10.1051/0004-6361/201117064
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发表时间：
2011-01
期刊：
影响因子：
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通讯作者：
L. Foschini;G. Ghisellini;F. Tavecchio;G. Bonnoli;A. Stamerra
中科院分区：
文献类型：
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作者：
L. Foschini;G. Ghisellini;F. Tavecchio;G. Bonnoli;A. Stamerra
我们报道了三个平谱射电类星体（3C 454.3, 3C 273, PKS B1222+216）的高能伽玛射线能量带的短期变化，它们在E > 100 MeV的通量超过10^-5 ph cm^-2 s^-1至少一天。虽然统计数据还不足以有效测量特征时间尺度，但它使我们能够为观测到的加倍时间尺度（< 2-3小时）设定严格的上限——这是迄今为止在MeV能量下测量到的最小时间尺度——这可以限制伽马射线发射区域的大小。在本工作中获得的结果支持伽马射线是在宽线区域内产生的假设。
We report about the search for short-term variability in the high-energy gamma-ray energy band of three flat-spectrum radio quasars (3C 454.3, 3C 273, PKS B1222+216), whose flux at E > 100 MeV exceeded the value of 10^-5 ph cm^-2 s^-1 for at least one day. Although, the statistics was not yet sufficient to effectively measure the characteristic time scale, it allowed us to set tight upper limits on the observed doubling time scale (< 2-3 hours) -- the smallest measured to date at MeV energies --, which can constrain the size of the gamma-ray emitting region. The results obtained in the present work favor the hypothesis that gamma rays are generated inside the broad-line region.