The Cosmic γ-ray Background from supernovae
The Cosmic γ-ray Background from supernovae
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DOI：
10.1063/1.53933
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发表时间：
2008-04
期刊：
影响因子：
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通讯作者：
Koki Watanabe;D. Hartmann;M. Leising;G. Share;R. Kinzer
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文献类型：
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作者：
Koki Watanabe;D. Hartmann;M. Leising;G. Share;R. Kinzer
在光子能量Eγ <$1MeV附近的宇宙γ射线背景（CGB）可能部分甚至完全是由超新星的γ射线产生引起的。特别地，来自衰变链56 Ni → 56 Co → 56 Fe（847，1238，1770，2599，2030，3250 keV）的γ射线线发射是SN诱导的CGB的主要来源。虽然铁的合成发生在所有类型的超新星中，但SNIa主要是由于较高的光子逃逸概率而对背景产生贡献。对局部宇宙中的整体星星形成历史的估计，得出现今的速率密度为103.7 ×10−2 h3 M <$Mpc−3 yr−1，但在红移为1阶时，星星形成速率大约高出10倍。然后速率再次下降，达到今天的值，接近红移1.5。除了来自SNIa的γ射线外，我们还考虑了来自SNII的谱线对CGB的贡献（例如1.8 MeV的26 Al，1.157 MeV的44 Ti和1.17 & 1.33 MeV的60 Co）。对平托和Woosley [8]的W 10 HMM模型的γ能谱进行了时间积分，得到了一个γ能谱的模板。
The Cosmic γ-ray Background (CGB) near photon energies Eγ∼1 MeV may be partly, or even completely, due to γ-ray production in supernovae. In particular, γ-ray line emission from the decay chain 56Ni→56Co→56Fe (847, 1238, 1770, 2599, 2030, 3250 keV) is the dominant source for the SN-induced CGB. Although iron synthesis occurs in all types of supernovae, SNIa contribute predominantly to the background mostly due to higher photon escape probabilities. Estimates of the global star formation history in the local universe yield a present-day rate density of ≃3.7×10−2 h3 M⊙ Mpc−3 yr−1, but the star formation rate was about ten times higher at a redshift of order unity. The rate then decreases again, reaching the present-day value near redshifts ≃5. In addition to γ-rays from SNIa we also consider contributions to the CGB due to lines from SNII (such as 26Al at 1.8 MeV, 44Ti at 1.157 MeV, and 60Co at 1.17 & 1.33 MeV). The γ-ray spectrum of Model W10HMM (Pinto & Woosley [8]) was time integrated to derive a templat...