SENSITIVITY OF THE CHERENKOV TELESCOPE ARRAY TO THE DETECTION OF INTERGALACTIC MAGNETIC FIELDS
SENSITIVITY OF THE CHERENKOV TELESCOPE ARRAY TO THE DETECTION OF INTERGALACTIC MAGNETIC FIELDS
复制标题
DOI：
10.3847/0004-637x/827/2/147
复制
发表时间：
2016-03
期刊：
影响因子：
--
通讯作者：
M. Meyer;J. Conrad;H. Dickinson
中科院分区：
文献类型：
--
作者：
M. Meyer;J. Conrad;H. Dickinson
来自河外源的高能（VHE；能量E≥100 GeV） γ射线与背景辐射场的低能光子发生配对。这些光子对可以逆康普顿散射背景光子，从而引发电磁级联。次级γ射线信号的时空结构随着它们在星系间磁场（IGMF）中的偏转而改变。我们研究了未来切伦科夫望远镜阵列的高角度分辨率和宽能量范围的VHE观测如何能够潜在地探测IGMF。我们确定了有希望的源，并使用公开可用的ELMAG蒙特卡罗代码在大范围的IGMF强度和相干长度值上模拟γ射线谱。结合联合似然方法的模拟观测，我们发现IGMF的当前限制可以显著改善。投射灵敏度在很大程度上取决于源处于γ射线活动状态的时间和发射的最大γ射线能量。
Very high energy (VHE; energy E ≳ 100 GeV) γ-rays originating from extragalactic sources undergo pair production with low-energy photons of background radiation fields. These pairs can inverse-Compton-scatter background photons, initiating an electromagnetic cascade. The spatial and temporal structure of this secondary γ-ray signal is altered as the pairs are deflected in an intergalactic magnetic field (IGMF). We investigate how VHE observations with the future Cherenkov Telescope Array, with its high angular resolution and broad energy range, can potentially probe the IGMF. We identify promising sources and simulate γ-ray spectra over a wide range of values of the IGMF strength and coherence length using the publicly available ELMAG Monte Carlo code. Combining simulated observations in a joint likelihood approach, we find that current limits on the IGMF can be significantly improved. The projected sensitivity depends strongly on the time a source has been γ-ray active and on the emitted maximum γ-ray energy.