The detection and flux estimation of point sources in cosmic microwave background (CMB) maps is a very important task in order to clean the maps and also to obtain relevant astrophysical information. In this paper we propose a maximum a posteriori (MAP) approach detection method in a Bayesian scheme which incorporates prior information about the source flux distribution, the locations and the number of sources. We apply this method to CMB simulations with the characteristics of the Planck satellite channels at 30, 44, 70 and 100 GHz. With a similar level of spurious sources, our method yields more complete catalogues than the matched filter with a 5σ threshold. Besides, the new technique allows us to fix the number of detected sources in a non-arbitrary way.

The authors acknowledge partial financial support from the Spanish Ministerio de Ciencia e Innovación project AYA2007-68058-C03- 02 and from the joint CNR-CSIC research project 2008-IT-0059. KK was supported by the Italian Space Agency, ASI, under the programme on Cosmology and Fundamental Physics, and by the TRIL programme at the Abdus Salam International Centre of Theoretical Physics, through a specific collaboration agreement with ISTI-CNR. ES and EEK acknowledge support from ASI through ASI/INAF Agreement I/072/09/0 for the Planck LFI Activity of Phase E2.

8 páginas, 9 figuras, 1 tabla.-- El Pdf del artículo es la versión pre-print: arXiv:1101.1456v1.-- et al.

Peer reviewed