Planck intermediate results. LIV. The Planck Multi-frequency Catalogue
  of Non-thermal Sources
  This paper presents the Planck Multi-frequency Catalogue of Non-thermal (i.e.
synchrotron-dominated) Sources (PCNT) observed between 30 and 857 GHz by the
ESA Planck mission. This catalogue was constructed by selecting objects
detected in the full mission all-sky temperature maps at 30 and 143 GHz, with a
signal-to-noise ratio (S/N)>3 in at least one of the two channels after
filtering with a particular Mexican hat wavelet. As a result, 29400 source
candidates were selected. Then, a multi-frequency analysis was performed using
the Matrix Filters methodology at the position of these objects, and flux
densities and errors were calculated for all of them in the nine Planck
channels. The present catalogue is the first unbiased, full-sky catalogue of
synchrotron-dominated sources published at millimetre and submillimetre
wavelengths and constitutes a powerful database for statistical studies of
non-thermal extragalactic sources, whose emission is dominated by the central
active galactic nucleus. Together with the full multi-frequency catalogue, we
also define the Bright Planck Multi-frequency Catalogue of Non-thermal Sources
PCNTb, where only those objects with a S/N>4 at both 30 and 143 GHz were
selected. In this catalogue 1146 compact sources are detected outside the
adopted Planck GAL070 mask; thus, these sources constitute a highly reliable
sample of extragalactic radio sources. We also flag the high-significance
subsample PCNThs, a subset of 151 sources that are detected with S/N>4 in all
nine Planck channels, 75 of which are found outside the Planck mask adopted
here. The remaining 76 sources inside the Galactic mask are very likely
Galactic objects.
