We conduct a first comprehensive study of the Luminosity Function (LF) using a non-parametric approach. We use Gaussian Process to fit available luminosity data between redshifts z ∼ 2-8. Our free-form LF in the non-parametric approach rules out the conventional Schechter function model to describe the abundance-magnitude relation at redshifts z=3 and 4. Hints of deviation from the Schechter function are also noticed at redshifts 2, 7 and 8 at lower statistical significance. Significant deviation starts for brighter ionizing sources at MUV ≲ -21. The UV luminosity density data at different redshifts are then derived by integrating the LFs obtained from both methods with a truncation magnitude of -17. In our analysis, we also include the first 90 arcmin2 JWST/NIRCam data at z ∼ 9-12. Since at larger magnitudes, we do not find major deviations from the Schechter function, the integrated luminosity density differs marginally between the two methods. Finally, we obtain the history of reionization from a joint analysis of UV luminosity density data along with the ionization fraction data and Planck observation of Cosmic Microwave Background. The history of reionization is not affected by the deviation of LFs from Schechter function at lower magnitudes. We derive reionization optical depth to be τre = 0.0494+0.0007-0.0006 and the duration between 10% and 90% completion of ionization process is found to be Δ z ∼ 1.627+0.059-0.071.

中文翻译：

---

紫外光度函数和再电离纪元的模型无关重建


我们使用非参数方法对亮度函数 （LF） 进行了首次全面研究。我们使用高斯过程在红移 z ∼ 2-8 之间拟合可用的光度数据。我们在非参数方法中的自由形式 LF 排除了传统的 Schechter 函数模型来描述红移 z=3 和 4 时的丰度-幅度关系。在红移 2、 7 和 8 处也注意到偏离 Schechter 函数的迹象，统计显著性较低。较亮的电离源在 MUV ≲ -21 时开始出现显著偏差。然后，通过将两种方法获得的 LF 积分得出不同红移下的 UV 光度密度数据，截断幅度为 -17。在我们的分析中，我们还包括 z ∼ 9-12 处的前 90 arcmin2 JWST/NIRCam 数据。由于在较大的星等下，我们没有发现与 Schechter 函数的重大偏差，因此两种方法之间的积分光度密度略有不同。最后，我们从紫外光度密度数据以及电离分数数据和宇宙微波背景的普朗克观测的联合分析中获得再电离的历史。再电离的历史不受较低幅度 LF 与 Schechter 函数的偏差的影响。我们推导出再电离光深度为 τre = 0.0494+0.0007-0.0006，发现电离过程完成 10% 至 90% 之间的持续时间为 Δ z ∼ 1.627+0.059-0.071。