标题： LOFAR两米天空调查深场——数据发布1：四。光度红移和恒星质量 显示英文标题

标题： The LOFAR Two-metre Sky Survey Deep Fields -- Data Release 1: IV. Photometric redshifts and stellar masses

摘要： 低频阵列（LOFAR）两米天空调查（LoTSS）是一项灵敏度高、分辨率高的120-168 MHz调查，覆盖北天区的多个层级。 第一次LoTSS深度场数据发布包括对Boötes、欧洲大区域红外空间观测站调查-北1（ELAIS-N1）和Lockman Hole场在150 MHz处的深度射电连续谱成像，达到均方根灵敏度分别为$\sim$32、20和22$\mu$Jy beam$^{-1}$。 在本文中，我们为所有三个场中的光学源目录提供了一致的光度红移（photo-$z$）估计值——总计超过700万个源（$\sim5$百万个源，限制在最佳光度覆盖区域后）。 我们的photo-$z$估计使用了一种混合方法，结合模板拟合和机器学习，并针对射电连续谱选择的源和更广泛的光学源群体优化了性能。 将我们的结果与光谱红移样本进行比较，我们发现星系的稳健散射范围从1.6%到2%，而识别出的光学、红外或X射线选择的活动星系核（AGN）的散射范围从6.4%到7%。 对应子集的异常值分数（$\left | z_{\text{phot}} - z_{\text{spec}} \right | / (1+z_{\text{spec}}) > 0.15$）分别从1.5%到1.8%和18%到22%。 与之前大范围射电巡天分析中看到的趋势相似，我们发现对于固定的红移，光-$z$质量随射电光度的变化没有明显的趋势。 我们利用每个场内宽波长覆盖的优势，为所有光学源在 $z < 1.5$处生成星系恒星质量估计值。 为每个场导出的恒星质量函数用于验证我们的质量估计，结果在各场之间以及与文献中的已发表结果相符。 显示英文摘要

摘要： The Low Frequency Array (LOFAR) Two-metre Sky Survey (LoTSS) is a sensitive, high-resolution 120-168 MHz survey split across multiple tiers over the northern sky. The first LoTSS Deep Fields data release consists of deep radio continuum imaging at 150 MHz of the Bo\"{o}tes, European Large Area Infrared Space Observatory Survey-North 1 (ELAIS-N1), and Lockman Hole fields, down to rms sensitivities of $\sim$32, 20, and 22 $\mu$Jy beam$^{-1}$, respectively. In this paper we present consistent photometric redshift (photo-$z$) estimates for the optical source catalogues in all three fields - totalling over 7 million sources ($\sim5$ million after limiting to regions with the best photometric coverage). Our photo-$z$ estimation uses a hybrid methodology that combines template fitting and machine learning and is optimised to produce the best possible performance for the radio continuum selected sources and the wider optical source population. Comparing our results with spectroscopic redshift samples, we find a robust scatter ranging from 1.6 to 2% for galaxies and 6.4 to 7% for identified optical, infrared, or X-ray selected active galactic nuclei (AGN). Our estimated outlier fractions ($\left | z_{\text{phot}} - z_{\text{spec}} \right | / (1+z_{\text{spec}}) > 0.15$) for the corresponding subsets range from 1.5 to 1.8% and 18 to 22%, respectively. Replicating trends seen in analyses of previous wide-area radio surveys, we find no strong trend in photo-$z$ quality as a function of radio luminosity for a fixed redshift. We exploit the broad wavelength coverage available within each field to produce galaxy stellar mass estimates for all optical sources at $z < 1.5$. Stellar mass functions derived for each field are used to validate our mass estimates, with the resulting estimates in good agreement between each field and with published results from the literature.