  We present the first all-sky catalogue of galaxy clusters and cluster
candidates obtained from joint X-ray-SZ detections using observations from the
Planck satellite and the ROSAT all-sky survey (RASS). The catalogue contains
2323 objects and has been validated by careful cross-identification with
previously known clusters. This validation shows that 1597 candidates
correspond to already known clusters, 212 coincide with other cluster
candidates still to be confirmed, and the remaining 514 are completely new
detections. With respect to Planck catalogues, the ComPRASS catalogue is
simultaneously more pure and more complete. Based on the validation results in
the SPT and SDSS footprints, the expected purity of the catalogue is at least
84.5%, meaning that more than 365 clusters are expected to be found among the
new or still to be confirmed candidates with future validation efforts or
specific follow-ups.
