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arXiv 1606.09293astro-ph.HE
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级联光子作为UHECR中质子的检验

Cascade photons as test of protons in UHECR

V. Berezinsky, A. Gazizov, O. Kalashev

摘要:

费米LAT测量的高能$γ$射线谱的各向同性分量约束了UHECR的质子分量。最强的限制来自最高的$(580-820)$ GeV能量仓。对质子分量的另一个限制是由冰立方提供的对高能宇宙成因中微子通量的上限。我们研究了这些限制对源性质的影响,如源的演化和分布,它们的能谱和核的混合。我们还研究了各种费米LAT银河前景模型(模型B的限制较少),河外背景光模型的选择和整体正常化的能谱的限制的敏感性。我们认为,$γ$ -射线级联约束比中微子约束更强,而且无论多少质子模型都是可行的。这种模型的基本参数是相对大的$γ_g$和不是很大的$z_{\max}$。允许使用H $e^4$混合物也放宽了限制。然而,我们预见到,未来CTA测量的$γ$ -射线谱在$E_γ\simeq (600 - 800)$ GeV,以及解决更多的个人$γ$ -射线源,可能会排除质子主导的宇宙射线模型。

英文摘要:

An isotropic component of high energy $γ$-ray spectrum measured by Fermi LAT constrains the proton component of UHECR. The strongest restriction comes from the highest, $(580-820)$ GeV, energy bin. One more constraint on the proton component is provided by the IceCube upper bound on ultrahigh energy cosmogenic neutrino flux. We study the influence of these restrictions on the source properties, such as evolution and distribution of sources, their energy spectrum and admixture of nuclei. We also study the sensitivity of restrictions to various Fermi LAT galactic foreground models (model B being less restrictive), to the choice of extragalactic background light model and to overall normalization of the energy spectrum. We claim that the $γ$-ray-cascade constraints are stronger than the neutrino ones, and that however many proton models are viable. The basic parameters of such models are relatively large $γ_g$ and not very large $z_{\max}$. The allowance for H$e^4$ admixture also relaxes the restrictions. However we foresee that future CTA measurements of $γ$-ray spectrum at $E_γ\simeq (600 - 800)$ GeV, as well as resolving of more individual $γ$-ray sources, may rule out the proton-dominated cosmic ray models.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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