SELECTION EFFECTS IN GAMMA-RAY BURST CORRELATIONS: CONSEQUENCES ON THE RATIO BETWEEN GAMMA-RAY BURST AND STAR FORMATION RATES
SELECTION EFFECTS IN GAMMA-RAY BURST CORRELATIONS: CONSEQUENCES ON THE RATIO BETWEEN GAMMA-RAY BURST AND STAR FORMATION RATES
复制标题
DOI：
10.1088/0004-637x/800/1/31
复制
发表时间：
2014-12
期刊：
影响因子：
--
通讯作者：
M. Dainotti;R. Vecchio;N. Shigehiro;S. Capozziello
中科院分区：
文献类型：
--
作者：
M. Dainotti;R. Vecchio;N. Shigehiro;S. Capozziello
高达极高红移的可见伽马射线暴（GRB）已成为有吸引力的目标，作为潜在的新距离指示器。目前尚不清楚迄今为止提出的关系是否源于未知的伽玛射线暴物理学，还是选择效应的结果。我们在平台期结束时的 X 射线光度 LX(Ta)、Ta 和静止帧时间之间的 LX-（以下简称 LT）相关性的情况下研究这个问题。我们设计了一种通用方法来从 GRB 世界模型开始构建模拟数据集，并考虑对时间和光度的选择影响。该方法表明，不知道效率函数会如何影响对任何相关性的固有斜率和伽玛暴密度率的评估。我们研究了由于截断而在 LT 关系中出现的偏差（斜率或归一化中的小偏移），这些偏差可能存在于 LX 和 的内在分布中。我们将这些结果与 Dainotti 等人的结果进行比较。显示在这两种情况下 LT 相关性的固有斜率都是 ≈ − 1.0。该方法是通用的，因此与调查偏差本身是否产生任何其他 GRB 相关性相关。此外，由于最远的GRB和恒星形成星系探测再电离时期，我们评估了GRB速率与恒星形成速率的红移相关比率Ψ(z) = (1 + z)α。我们发现适度的演化−0.2 ⩽ α ⩽ 0.5 与红移范围 0.99 < z < 9.4 中的 Swift GRB 余辉平台一致。
Gamma-ray bursts (GRBs) visible up to very high redshift have become attractive targets as potential new distance indicators. It is still not clear whether the relations proposed so far originate from an unknown GRB physics or result from selection effects. We investigate this issue in the case of the LX– (hereafter LT) correlation between the X-ray luminosity LX(Ta) at the end of the plateau phase, Ta, and the rest-frame time . We devise a general method to build mock data sets starting from a GRB world model and taking into account selection effects on both time and luminosity. This method shows how not knowing the efficiency function could influence the evaluation of the intrinsic slope of any correlation and the GRB density rate. We investigate biases (small offsets in slope or normalization) that would occur in the LT relation as a result of truncations, possibly present in the intrinsic distributions of LX and . We compare these results with the ones in Dainotti et al. showing that in both cases the intrinsic slope of the LT correlation is ≈ − 1.0. This method is general and therefore relevant for investigating whether or not any other GRB correlation is generated by the biases themselves. Moreover, because the farthest GRBs and star-forming galaxies probe the reionization epoch, we evaluate the redshift-dependent ratio Ψ(z) = (1 + z)α of the GRB rate to the star formation rate. We found a modest evolution −0.2 ⩽ α ⩽ 0.5 consistent with a Swift GRB afterglow plateau in the redshift range 0.99 < z < 9.4.