标题： 坍缩星伽马射线暴的光度函数：长伽马射线暴的前身并非单一 显示英文标题

标题： Luminosity Function of collapsar Gamma-Ray Bursts:the Progenitor of Long Gamma-Ray Bursts Is Not Singular

摘要： 伽马射线暴（GRBs）是探测高红移宇宙的强大工具。然而，长伽马射线暴中的 collapsar GRB 所占比例及其相对于恒星形成率（SFR）的事件率仍然是有争议的问题。 我们假设所有具有 $z\geq 2$ 的长伽马射线暴都是 collapsar GRB，并使用来自 Swift 卫星从 2004 年到 2019 年的高红移样本构建了亮度函数。 我们将亮度函数建模为带有断点的幂律形式，并考虑了三种情况：无演化、光度演化和密度演化。 我们的结果如下：1) 无演化模型可以排除。 2) 拟合结果显示，为了充分解释观测结果，需要显著的红移演化，无论是光度演化（演化指数 $\delta = 1.54^{+0.21}_{-0.22}$），还是密度演化（$\delta = 2.09^{+0.29}_{-0.26}$）。这排除了长伽马射线暴随红移演化是由非-collapsar GRB 污染的可能性。 3) 光度演化模型预测，具有 $z<2$ 和 $P \geq 1 \, \text{ph} \, \text{cm}^{-2} \, \text{s}^{-1}$的 collapsar GRB 数量为 138.6，占到观测到的 $z<2$ 和 $P \geq 1 \, \text{ph} \, \text{cm}^{-2} \, \text{s}^{-1}$ 的长伽马射线暴的 82.5%。 密度演化模型预测的具有 $z<2$ 和 $P \geq 1 \, \text{ph} \, \text{cm}^{-2} \, \text{s}^{-1}$ 的 collapsar 伽马射线暴的数量为 80.2，占观测值的 47.7%。 无论模型如何，大量长伽马射线暴都不是 collapsar 伽马射线暴。 显示英文摘要

摘要： Gamma-ray bursts (GRBs) are powerful probes of the high-redshift universe. However, the proportion of collapsar GRBs among long GRBs and their event rate relative to the star formation rate (SFR) remain contentious issues. We assume that long GRBs with $z\geq 2$ are all collapsar GRBs and construct the luminosity function using a high-redshift sample from the Swift satellite spanning 2004 to 2019. We model the luminosity function with a broken power-law form and consider three scenarios: no evolution, luminosity evolution, and density evolution. Our results are as follows: 1) The no-evolution model can be ruled out. 2) The fitting results indicate that to adequately explain the observations, a significant redshift evolution in either luminosity (evolution index $\delta = 1.54^{+0.21}_{-0.22}$) or density ($\delta = 2.09^{+0.29}_{-0.26}$) is required. This excludes the possibility that the evolution of long GRBs with redshift is due to contamination from non-collapsar GRBs. 3) The luminosity evolution model predicts that the number of collapsar GRBs with $z<2$ and $P \geq 1 \, \text{ph} \, \text{cm}^{-2} \, \text{s}^{-1}$ is 138.6, accounting for 82.5% of the observed long GRBs with $z<2$ and $P \geq 1 \, \text{ph} \, \text{cm}^{-2} \, \text{s}^{-1}$. The density evolution model predicts that the number of collapsar GRBs with $z<2$ and $P \geq 1 \, \text{ph} \, \text{cm}^{-2} \, \text{s}^{-1}$ is 80.2, accounting for 47.7% of the observation. Regardless of the model, a substantial portion of the long GRBs are not collapsar GRBs.