"PowellSnakes", a fast Bayesian detection method of compact objects. The extraction of Planck's nominal SZ clusters of galaxies catalogue

Pedro Carvalho
Kavli Institute for Cosmology, Cambridge

"PowellSnakes" (PwS) is a fast Bayesian algorithm designed for detecting compact objects immersed in a diffuse background. PwS was selected and successfully employed by the Planck consortium in the production of its first public deliverable: the Early Release Compact Source Catalogue (ERCSC) and later as an extraction/characterisation tool of Planck's nominal mission Sunyaev–Zel’dovich (SZ) clusters of galaxies catalogue. We present the reasons why Planck's SZ catalogue needed a Bayesian method and why a simple naïve implementation was not practical. An emphasis is placed on the necessity of a multi-frequency, multi-model detection algorithm in order to achieve optimality.

19 abril 2013, 13:30

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