Galactic Cold Cores IV. Cold sub-millimetre sources: catalogue and statistical analysis

Abstract

International audienceContext. For the project Galactic cold cores, Herschel photometric observations were carried out as a follow-up of cold regions of interstellar clouds previously identified with the Planck satellite. The aim of the project is to derive the physical properties of the population of cold sources and to study its connection to ongoing and future star formation.Aims.We build a catalogue of cold sources within the clouds in 116 fields observed with the Herschel PACS and SPIRE instruments.We wish to determine the general physical characteristics of the cold sources and to examine the correlations with their host cloud properties.Methods. From Herschel data, we computed colour temperature and column density maps of the fields. We estimated the distance to the target clouds and provide both uncertainties and reliability flags for the distances. The getsources multiwavelength source extraction algorithm was employed to build a catalogue of several thousand cold sources. Mid-infrared data were used, along with colour and position criteria, to separate starless and protostellar sources. We also propose another classification method based on submillimetre temperature profiles. We analysed the statistical distributions of the physical properties of the source samples