论文标题
在FRB光度函数上 - ii。事件速率密度
On the FRB luminosity function -- II. Event rate density
论文作者
论文摘要
快速无线电爆发（FRB）的光度函数定义为单位宇宙亮度的每单位宇宙共同移动量的事件速率，可能有助于揭示FRB的可能起源并设计最佳搜索策略。使用贝叶斯建模，我们使用46个已知FRB测量FRB光度函数。我们的贝叶斯框架是自愿建模的选择效果，包括调查敏感性，望远镜梁响应以及来自银河系 /宿主星系 /局部FRB的宿主星系 /本地环境的电子分布。与以前的同伴论文不同，我们注意FRB事件速率密度，并根据Poisson统计数据对FRB调查的事件计数进行建模。假设采用Schechter的发光函数表格，我们（在95％的置信度下），在上截止截止度上的特征性frb事件速率密度$ l^*= 2.9 _ { - 1.7}^{+11.9} {+11.9} \ times10^{44} {44} {44} {44} \， $ ϕ^*= 339 _ { - 313}^{+1074} \，\ rm gpc^{ - 3} \，yr^{ - 1} $，powerlaw索引为$α= -1.79 _ { - 0.35} $ l_0 \ le9.1 \ times10^{41} \，\ rm erg \，s^{ - 1} $。发现FRB的事件速率密度被发现为$ 3.5 _ { - 2.4}^{+5.7} \ times10^4 \，\ rm gpc^{ - 3} \，yr^{ - 1} $ apper $ 10^{42} {42}} $ 5.0 _ { - 2.3}^{+3.2} \ times10^3 \，\ rm gpc^{ - 3} \，yr^{ - 1} $ aff $ 10^{43} {43} \，\ rm Erg \ rm erg \，S^{ - 1} $，and and和$ 3.7 _ { - 2.0}^{+3.5} \ times10^2 \，\ rm gpc^{ - 3} \，yr^{ - 1} $上方$ 10^{44} {44} \，\ rm erg erg erg \，s^{ - 1} $。结果，我们发现，对于以1.4 GHz进行的搜索，单次射电望远镜的最佳直径检测到FRB的最佳直径为30-40 m。当前论文还讨论了测量事件速率密度的天体物理含义。
The luminosity function of Fast Radio Bursts (FRBs), defined as the event rate per unit cosmic co-moving volume per unit luminosity, may help to reveal the possible origins of FRBs and design the optimal searching strategy. With the Bayesian modelling, we measure the FRB luminosity function using 46 known FRBs. Our Bayesian framework self-consistently models the selection effects, including the survey sensitivity, the telescope beam response, and the electron distributions from Milky Way / the host galaxy / local environment of FRBs. Different from the previous companion paper, we pay attention to the FRB event rate density and model the event counts of FRB surveys based on the Poisson statistics. Assuming a Schechter luminosity function form, we infer (at the 95% confidence level) that the characteristic FRB event rate density at the upper cut-off luminosity $L^*=2.9_{-1.7}^{+11.9}\times10^{44}\,\rm erg\, s^{-1}$ is $ϕ^*=339_{-313}^{+1074}\,\rm Gpc^{-3}\, yr^{-1}$, the power-law index is $α=-1.79_{-0.35}^{+0.31}$, and the lower cut-off luminosity is $L_0\le9.1\times10^{41}\,\rm erg\, s^{-1}$. The event rate density of FRBs is found to be $3.5_{-2.4}^{+5.7}\times10^4\,\rm Gpc^{-3}\, yr^{-1}$ above $10^{42}\,\rm erg\, s^{-1}$, $5.0_{-2.3}^{+3.2}\times10^3\,\rm Gpc^{-3}\, yr^{-1}$ above $10^{43}\,\rm erg\, s^{-1}$, and $3.7_{-2.0}^{+3.5}\times10^2\,\rm Gpc^{-3}\, yr^{-1}$ above $10^{44}\,\rm erg\, s^{-1}$. As a result, we find that, for searches conducted at 1.4 GHz, the optimal diameter of single-dish radio telescopes to detect FRBs is 30-40 m. The possible astrophysical implications of the measured event rate density are also discussed in the current paper.
