Montanino Daniele, Vazza Franco, Mirizzi Alessandro, Viel Matteo
Dipartimento di Matematica e Fisica "Ennio de Giorgi," Università del Salento, Via Arnesano, I-73100 Lecce, Italy.
Istituto Nazionale di Fisica Nucleare-Sezione di Lecce, Via Arnesano, I-73100 Lecce, Italy.
Phys Rev Lett. 2017 Sep 8;119(10):101101. doi: 10.1103/PhysRevLett.119.101101. Epub 2017 Sep 5.
Large-scale extragalactic magnetic fields may induce conversions between very-high-energy photons and axionlike particles (ALPs), thereby shielding the photons from absorption on the extragalactic background light. However, in simplified "cell" models, used so far to represent extragalactic magnetic fields, this mechanism would be strongly suppressed by current astrophysical bounds. Here we consider a recent model of extragalactic magnetic fields obtained from large-scale cosmological simulations. Such simulated magnetic fields would have large enhancement in the filaments of matter. As a result, photon-ALP conversions would produce a significant spectral hardening for cosmic TeV photons. This effect would be probed with the upcoming Cherenkov Telescope Array detector. This possible detection would give a unique chance to perform a tomography of the magnetized cosmic web with ALPs.
大规模星系际磁场可能会诱导甚高能光子与类轴子粒子（ALP）之间的转换，从而使光子免受星系际背景光吸收的影响。然而，在目前用于表示星系际磁场的简化“单元”模型中，这一机制会受到当前天体物理学限制的强烈抑制。在此，我们考虑一种从大规模宇宙学模拟中获得的星系际磁场最新模型。这种模拟磁场在物质细丝中会有大幅增强。结果，光子 - ALP转换会使宇宙TeV光子产生显著的光谱硬化。即将启用的切伦科夫望远镜阵列探测器将探测到这种效应。这种可能的探测将为利用ALP对磁化宇宙网进行层析成像提供独特机会。
