The <i>Planck</i> SZiFi catalogues: a new set of <i>Planck</i> catalogues of Sunyaev–Zeldovich-detected galaxy clusters

ABSTRACT We introduce the Planck SZiFi catalogues, a new set of 10 catalogues of galaxy clusters detected through their thermal Sunyaev–Zeldovich (tSZ) signature. The catalogues are produced by applying the SZiFi cluster finder to the Planck PR3 temperature data down to a signal-to-noise threshold of 5. They span three frequency channel combinations (100–857, 100–545, and 100–353 GHz) and seven of them are constructed by spectrally deprojecting the Cosmic Infrared Background (CIB). This approach allows us, for the first time in the context of cluster finding, to carefully assess the impact of the cluster-correlated CIB on the recovered cluster tSZ observables, which we find to be negligible. In addition, we quantify the impact of the relativistic corrections to the tSZ signal, finding them to be at the 5–10 per cent level for the cluster tSZ amplitude but negligible for the signal-to-noise ratio. We compile our catalogues into a single Planck SZiFi master catalogue containing a total of 1499 detections. We cross-match the master catalogue with several external tSZ and X-ray cluster catalogues, setting a lower bound on the purity of our baseline iMMF6 catalogue of 96 per cent and 99 per cent at a minimum signal-to-noise ratios of 5 and 6, respectively. We validate our cluster detection pipeline by applying it to synthetic observations, recovering cluster number counts for which we are able to produce a theoretical prediction that accurately describes them. This validation exercise indicates that our catalogues are well-suited for cosmological inference. The Planck SZiFi master catalogue will become publicly available at https://github.com/inigozubeldia/szifi/tree/main/planck_szifi_master_catalogue.