Although interesting in themselves, extragalactic sources emitting in the microwave range (mainly radio-loud active galactic nuclei and dusty galaxies) are also considered a contaminant from the point of view of Cosmic Microwave Background (CMB) experiments. These sources appear as unresolved point-like objects in CMB measurements because of the limited resolution of CMB experiments. Amongst other issues, point-like sources are known to obstruct the reconstruction of the lensing potential, and can hinder the detection of the Primordial Gravitational Wave Background for low values of r. Therefore, extragalactic point-source detection and subtraction is a fundamental part of the component separation process necessary to achieve some of the science goals set for the next generation of CMB experiments. As a previous step to their removal, in this work we present a new filter based on steerable wavelets that allows the characterization of the emission of these extragalactic sources. Instead of the usual approach of working in polarization maps of the Stokes' Q and U parameters, the proposed filter operates on E- and B-mode polarization maps. In this way, it benefits from the lower intensity that, both, the CMB, and the galactic foreground emission, present in B-modes to improve its performance. To demonstrate its potential, we have applied the filter to simulations of the future PICO satellite, and we predict that, for the regions of fainter galactic foreground emission in the 30 GHz and 155 GHz bands of PICO, our filter will be able to characterize sources down to a minimum polarization intensity of, respectively, 125 pK and 14 pK. Adopting a Π=0.02 polarization degree, these values correspond to 169 mJy and 288 mJy intensities.

尽管本身很有趣，但从宇宙微波背景 (CMB) 实验的角度来看，在微波范围内发射的河外源（主要是无线电响亮的活动星系核和尘埃星系）也被认为是污染物。由于 CMB 实验的分辨率有限，这些源在 CMB 测量中显示为未解析的点状物体。除其他问题外，已知点状源会阻碍透镜势的重建，并且会阻碍对低 r 值的原始引力波背景的检测。因此，河外点源检测和减法是实现为下一代 CMB 实验设定的某些科学目标所必需的组件分离过程的基本部分。作为移除它们的前一步，在这项工作中，我们提出了一种基于可控小波的新滤波器，可以表征这些河外源的发射。与在斯托克斯 Q 和 U 参数的偏振图中工作的通常方法不同，所提出的滤波器对 E 和 B 模式偏振图进行操作。通过这种方式，它受益于 B 模式中存在的 CMB 和银河前景发射的较低强度，以提高其性能。为了证明其潜力，我们已将该滤波器应用于未来 PICO 卫星的模拟，并且我们预测，对于 PICO 的 30 GHz 和 155 GHz 频带中较暗的银河前景发射区域，我们的滤波器将能够表征源分别降至 125 pK 和 14 pK 的最小偏振强度。采用 Π=0.02 偏振度，