The TeV Diffuse Cosmic Neutrino Spectrum and the Nature of Astrophysical Neutrino Sources
The TeV Diffuse Cosmic Neutrino Spectrum and the Nature of Astrophysical Neutrino Sources
复制标题
DOI：
10.3847/1538-4357/ac7649
复制
发表时间：
2022-05
期刊：
影响因子：
--
通讯作者：
K. Fang;J. Gallagher;F. Halzen
中科院分区：
文献类型：
--
作者：
K. Fang;J. Gallagher;F. Halzen
冰立方天文台测量了从TeV能量到PeV能量的宇宙中微子扩散通量。我们表明，在较低能量TeV和亚TeV下对这种通量的改进表征，以一种与模型无关的方式揭示了关于天体物理中微子源性质的重要信息。最重要的是，它可以证实目前的迹象，即中微子起源于光学厚度超过GeV-TeVγ-射线的宇宙环境。如果在TeV区观察到不间断甚至更陡峭的中微子幂定律，这一结论将是不可避免的。在这种被γ射线遮挡的源中，不可避免地伴随着宇宙中微子的γ射线将向下倾泻到MeV-GeV能量。伴随宇宙中微子的级联γ射线通量不应超过观测到的漫射γ射线背景的要求，对源中辐射场的峰值能量和密度提出了限制。我们受现有数据启发的计算表明，观测到的弥散MeV-GeVγ射线背景的一部分可能是由具有强烈辐射场的中微子源贡献的，这些辐射场掩盖了伴随中微子发出的高能γ射线。
The diffuse flux of cosmic neutrinos has been measured by the IceCube Observatory from TeV to PeV energies. We show that an improved characterization of this flux at lower energies, TeV and sub-TeV, reveals important information on the nature of the astrophysical neutrino sources in a model-independent way. Most significantly, it could confirm the present indications that neutrinos originate in cosmic environments that are optically thick to GeV–TeV γ-rays. This conclusion will become inevitable if an uninterrupted or even steeper neutrino power law is observed in the TeV region. In such γ-ray-obscured sources, the γ-rays that inevitably accompany cosmic neutrinos will cascade down to MeV–GeV energies. The requirement that the cascaded γ-ray flux accompanying cosmic neutrinos should not exceed the observed diffuse γ-ray background puts constraints on the peak energy and density of the radiation fields in the sources. Our calculations inspired by the existing data suggest that a fraction of the observed diffuse MeV–GeV γ-ray background may be contributed by neutrino sources with intense radiation fields that obscure the high-energy γ-ray emission accompanying the neutrinos.