  We study the detection of extragalactic point sources in two-dimensional flat
simulations for all the frequencies of the forthcoming ESA's Planck mission. In
this work we have used the most recent available templates of the microwave
sky: as for the diffuse Galactic components and the Sunyaev-Zel'dovich clusters
we have used the ``Plank Reference Sky Model''; as for the extragalactic point
sources, our simulations - which comprise all the source populations relevant
in this frequency interval - are based on up-to-date cosmological evolution
models for sources. To consistently compare the capabilities of different
filters for the compilation of the - hopefully - most complete blind catalogue
of point sources, we have obtained three catalogues by filtering the simulated
sky maps with: the Matched Filter (MF), the Mexican Hat Wavelet (MHW1) and the
Mexican Hat Wavelet 2 (MHW2), the first two members of the MHW Family. For the
nine Planck frequencies we show the number of real and spurious detections and
the percentage of spurious detections at different flux detection limits as
well as the completeness level of the catalogues and the average errors in the
estimation of the flux density of detected sources. Allowing a 5 % of spurious
detections, we obtain the following number of detections by filtering with the
MHW2 an area equivalent to half of the sky: 580 (30 GHz), 342 (44 GHz), 341 (70
GHz), 730 (100 GHz), 1130 (143 GHz), 1233 (217 GHz), 990 (353 GHz), 1025 (545
GHz) and 3183 (857 GHz). Our current results indicate that the MF and the MHW2
yield similar results, whereas the MHW1 performs worse in some cases and
especially at very low fluxes. This is a relevant result, because we are able
to obtain comparable results with the well known Matched Filter and with this
specific wavelet, the MHW2, which is much easier to implement and use.
