An adaptive filter for the construction of the Planck Compact Source Catalogue

We develop a linear algorithm to extract extragalactic point sources for the Compact Source Catalogue of the upcoming Planck mission. This algorithm is based on a simple top-hat filter in the harmonic domain with an adaptive filtering range which does not require a priori knowledge of the cosmic microwave background power spectrum, and experimental parameters such as the beam size and shape or the pixel noise level.