arXiv 0808.28842008-08-21astro-ph

探测宇宙微波背景图中点源的一种新的多频技术

A novel multi-frequency technique for the detection of point sources in Cosmic Microwave Background maps

D. Herranz, M. Lopez-Caniego, J. L. Sanz, J. Gonzalez-Nuevo

备注：: 12 pages, 10 figures, submitted to MNRAS
DOI：: 10.1111/j.1365-2966.2008.14336.x

摘要：

在这项工作中，我们解决的问题，同时多频探测河外点源的宇宙微波背景的地图。我们采用一种新的线性滤波技术，所谓的“匹配矩阵滤波器”，它采用了完整的空间信息，包括通道之间的互相关，而不作任何先验假设的频谱行为的来源。由于滤波图的最佳组合，实现了背景的大幅减少。我们详细描述了新技术，我们将其应用到现实的全天普朗克模拟在30，44，70和100 GHz的无线电源的检测/估计。然后，我们比较了结果的可靠性，完整性和通量精度的点源目录的单频方法的基础上，标准匹配滤波器。新滤波器在30、44和70 GHz的所有这些指标上都优于标准匹配滤波器，而在100 GHz，两种滤波器具有相似的性能。我们发现一个显着的增量为一个固定的可靠性水平的真实检测的数量。特别是，为了达到95%的可靠性，我们几乎将30、44和70 GHz的检测数量增加了一倍。

英文摘要：

In this work we address the problem of simultaneous multi-frequency detection of extragalactic point sources in maps of the Cosmic Microwave Background. We apply a new linear filtering technique, the so called `matched matrix filters', that incorporates full spatial information, including the cross-correlation among channels, without making any a priori assumption about the spectral behaviour of the sources. A substantial reduction of the background is achieved thanks to the optimal combination of filtered maps. We describe in detail the new technique and we apply it to the detection/estimation of radio sources in realistic all-sky Planck simulations at 30, 44, 70 and 100 GHz. Then we compare the results with the mono-frequential approach based on the standard matched filter, in terms of reliability, completeness and flux accuracy of the resulting point source catalogs. The new filters outperform the standard matched filters for all these indexes at 30, 44 and 70 GHz, whereas at 100 GHz both kind of filters have a similar performance. We find a noticeable increment of the number of true detections for a fixed reliability level. In particular, for a 95% reliability we practically double the number of detections at 30, 44 and 70 GHz.

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英文摘要：

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