Modeling Gamma‐Ray Attenuation in High Redshift GeV Spectra
Modeling Gamma‐Ray Attenuation in High Redshift GeV Spectra
复制标题
高红移 GeV 光谱中伽马射线衰减的建模
DOI：
10.1063/1.3076738
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
R. Somerville
中科院分区：
文献类型：
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作者：
R. Gilmore;P. Madau;J. Primack;R. Somerville
我们提出了两个模型的宇宙学紫外背景光，并计算了GeV的伽马射线的红移9的不透明度。背景的贡献者包括两个可能的类星体发射率，和最近的半解析模型（SAM）的结构形成所确定的恒星形成星系的输出。在这项工作中使用的SAM是基于一个在ΛCDM宇宙中的结构的分层建立，并且在再现各种观测参数方面非常成功。在1里德堡能量以上，电离辐射会受到IGM的再处理，我们使用我们的辐射传输代码CUBA处理。选择两个z = 2.3以上的类星体发射率模型，以匹配使用通量减量分析观察到的电离率和视线邻近效应的较高值。我们还研究了在z>5时flat星星形成率密度的可能性。我们的结论是，从10至100 GeV的费米（GLAST）和下一代的g射线的观测…
We present two models for the cosmological UV background light, and calculate the opacity of GeV gamma—rays out to redshift 9. The contributors to the background include 2 possible quasar emissivities, and output from star—forming galaxies as determined by recent a semi—analytic model (SAM) of structure formation. The SAM used in this work is based upon a hierarchical build‐up of structure in a ΛCDM universe and is highly successful in reproducing a variety of observational parameters. Above 1 Rydberg energy, ionizing radiation is subject to reprocessing by the IGM, which we treat using our radiative transfer code, CUBA. The two models for quasar emissivity differing above z = 2.3 are chosen to match the ionization rates observed using flux decrement analysis and the higher values of the line‐of‐sight proximity effect. We also investigate the possibility of aflat star formation rate density at z>5. We conclude that observations of gamma—rays from 10 to 100 GeV by Fermi (GLAST) and the next generation of g...