We present a point-source detection algorithm that employs the second-order Spherical Mexican Hat wavelet filter (SMHW2), and use it on C-Band All-Sky Survey (C-BASS) northern intensity data to produce a catalogue of point sources. This catalogue allows us to cross-check the C-BASS flux-density scale against existing source surveys, and provides the basis for a source mask that will be used in subsequent C-BASS and cosmic microwave background (CMB) analyses. The SMHW2 allows us to filter the entire sky at once, avoiding complications from edge effects arising when filtering small sky patches. The algorithm is validated against a set of Monte Carlo simulations, consisting of diffuse emission, instrumental noise, and various point-source populations. The simulated source populations are successfully recovered. The SMHW2 detection algorithm is used to produce a 4.76GHz northern sky source catalogue in total intensity, containing 1784 sources and covering declinations δ ≥ −10°. The C-BASS catalogue is matched with the Green Bank 6 cm (GB6) and Parkes-MIT-NRAO (PMN) catalogues over their areas of common sky coverage. From this we estimate the 90 per cent completeness level to be approximately 610mJy⁠, with a corresponding reliability of 98 per cent, when masking the brightest 30 per cent of the diffuse emission in the C-BASS northern sky map. We find the C-BASS and GB6 flux-density scales to be consistent with one another to within approximately 4 per cent.

中文翻译：

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C波段全天巡天：北方天空的总强度点源探测

我们提出了一种采用二阶球形墨西哥帽小波滤波器 (SMHW2) 的点源检测算法，并将其用于 C 波段全天调查 (C-BASS) 北方强度数据以生成点源目录。该目录使我们能够根据现有源调查交叉检查 C-BASS 通量密度标度，并为将用于后续 C-BASS 和宇宙微波背景 (CMB) 分析的源掩模提供基础。SMHW2 允许我们一次过滤整个天空，避免过滤小天空块时产生的边缘效应的复杂性。该算法针对一组蒙特卡罗模拟进行了验证，包括漫射发射、仪器噪声和各种点源种群。模拟源种群成功恢复。SMHW2检测算法用于生成总强度为4.76GHz的北方天空源目录，包含1784个源，覆盖偏角δ≥-10°。C-BASS 目录与 Green Bank 6 cm (GB6) 和 Parkes-MIT-NRAO (PMN) 目录在其共同天空覆盖区域内相匹配。据此，我们估计 90% 的完整性水平约为 610mJy，当掩盖 C-BASS 北部天空图中最亮的 30% 漫射发射时，相应的可靠性为 98%。我们发现 C-BASS 和 GB6 通量密度标度彼此一致，大约在 4% 以内。C-BASS 目录与 Green Bank 6 cm (GB6) 和 Parkes-MIT-NRAO (PMN) 目录在其共同天空覆盖区域内相匹配。据此，我们估计 90% 的完整性水平约为 610mJy，当掩盖 C-BASS 北部天空图中最亮的 30% 漫射发射时，相应的可靠性为 98%。我们发现 C-BASS 和 GB6 通量密度标度彼此一致，大约在 4% 以内。C-BASS 目录与 Green Bank 6 cm (GB6) 和 Parkes-MIT-NRAO (PMN) 目录在其共同天空覆盖区域内相匹配。据此，我们估计 90% 的完整性水平约为 610mJy，当掩盖 C-BASS 北部天空图中最亮的 30% 漫射发射时，相应的可靠性为 98%。我们发现 C-BASS 和 GB6 通量密度标度彼此一致，大约在 4% 以内。