Pedro Carvalho
Kavli Institute for Cosmology, Cambridge

Abstract
"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.

2013 April 19, 13:30

IA/U.Porto
Centro de Astrofísica da Universidade do Porto (Auditorium)
Rua das Estrelas, 4150-762 Porto