Fermi-LAT observations of extreme spectral variability in IC 310
Fermi-LAT observations of extreme spectral variability in IC 310
复制标题
IC 310 中极端光谱变化的 Fermi-LAT 观测
DOI：
10.1093/mnras/stz588
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发表时间：
2019
影响因子：
4.8
通讯作者：
Chadwick P
中科院分区：
文献类型：
--
作者：
Chadwick P
我们调查的物理机制，高能γ射线发射的TeV发射失调的活动星系核IC 310。本文对费米大天区望远镜（Fermi-LAT）在100 - 500 GeV能量范围内的8年观测数据进行了整理和分析，以研究IC 310的时间和光谱特性。点扩散函数划分的仪器响应函数被用来提高IC 310从附近的NGC 1275的可分辨性。系统的影响，由于这种选择的仪器响应函数和NGC 1275的接近进行了研究。我们发现了很强的光谱变化性，并检测到IC 310的硬耀斑状态沿着与以前未发现的软状态在静止期，和第一次检测与费米LAT低于1 GeV。这表示峰值康普顿能量的偏移超过5个数量级。可能的解释进行了讨论，但我们缺乏与费米探测潜在的物理瞬时灵敏度。
We investigate the physical mechanisms of high-energy gamma-ray emission from the TeV-emitting misaligned active galactic nucleus IC 310. 8 yr of data from theFermiLarge Area Telescope (Fermi-LAT) between 100 MeV and 500 GeV are reduced and analysed to study the temporal and spectral characteristics of IC 310. Point spread function-partitioned instrument response functions are used to improve the resolvability of IC 310 from nearby NGC 1275. Systematic effects due to this choice of instrument response functions and the proximity of NGC 1275 are investigated. We find strong spectral variability and detect the hard flaring state of IC 310 along with a previously undiscovered soft state in quiescent periods, and the first detection withFermi-LAT below 1 GeV. This represents a shift in peak Compton energy of more than 5 orders of magnitude. Possible interpretations are discussed, but we lack the instantaneous sensitivity withFermito probe the underlying physics.