Some good reasons to use matched filters for the detection of point sources in CMB maps

¹ Chip Computers Consulting s.r.l., Viale Don L. Sturzo 82, S. Liberale di Marcon, 30020 Venice, Italy ESA-VILSPA, Apartado 50727, 28080 Madrid, Spain
² Osservatorio Astronomico di Padova, vicolo dell' Osservatorio 5, 35122 Padua, Italy e-mail: andreani@pd.astro.it
³ ESA-VILSPA, Apartado 50727, 28080 Madrid, Spain e-mail: willem.wamsteker@esa.int

Corresponding author: R. Vio, robertovio@tin.it

Received: 15 August 2003
Accepted: 16 October 2003

Abstract

In this paper we comment on the results concerning the performances of matched filters, scale adaptive filters and Mexican hat wavelet that recently appeared in literature in the context of point source detection in Cosmic Microwave Background maps. In particular, we show that, contrary to what has been claimed, the use of the matched filters still appear to be the most reliable and efficient method to disantangle point sources from the backgrounds, even when using detection criterion that, differently from the classic thresholding rule, takes into account not only the height of the peaks in the signal corresponding to the candidate sources but also their curvature.