宇宙γ暴距离及分布  

Distance Scale and Distribution of the Cosmological γ-ray Bursts

作　　者：王彩芬[1] 韦大明[1] 

机构地区：[1]中国科学院紫金山天文台,南京210008

出　　处：《天文学报》2004年第1期42-47,共6页Acta Astronomica Sinica

基　　金：国家自然科学基金(10073022;10233010);杰出青年基金(10225314)和973项目资助

摘　　要：γ暴是宇宙空间中短时标γ射线突然增亮的现象.在考虑γ暴的宇宙膨胀效应、喷流效应、以及γ暴与超新星成协现象后研究了γ暴的空间分布,假设γ暴张角是高斯分布,爆发率与恒星形成率成正比,找到最佳拟合参数值为θ0=0.1,σ=1,可说明γ暴的张角集中在0.1附近,这与目前对已知红移的γ暴的分析是一致的.由<V/Vmax>计算得到γ暴的最远红移为4.2,γ暴的能量为1.5×1051ergs.γ-ray burst is an astronomical phenomenon of short duration enhancement of γ-rays from cosmic space. Considering the effect of the expansion of the universe, beaming effect and the evidence that γ ray bursts are close to star-forming regions, we study the distribution of the γray bursts. Assuming the opening angle follows Gauss distribution and γ ray bursts follow the measured star formation rate, we find the best parameters that fit the theory are θ0= 0.1,σ= 0.04. This shows that the most common angle is about O.lrad, in rough agreement with the samples whose redshift haven been known. The calculated maximum redshift from< v/vmax> is 4.2 and the energy of the γ-ray burst is 1.5 ×1051 ergs.

关 键 词：Γ射线 暴 宇宙膨胀 喷流 星系 

分 类 号：P159[天文地球—天文学] P172.3