Planck 2013 results. XXIX. Planck catalogue of Sunyaev-Zeldovich sources

TL;DR

Planck 2013 results XXIX present the Planck SZ catalogue (PSZ), the largest all-sky SZ-selected cluster sample derived from the first 15.5 months of Planck data. The catalogue comprises 1227 detections (861 confirmed clusters, including 178 new discoveries, and 366 cluster candidates), spanning redshifts up to $z\approx 1$ and cluster masses from $0.1$ to $1.6\times10^{15} M_\odot$, with 813 clusters having redshifts and a homogenized SZ mass proxy $Y_z$. The PSZ is built from three SZ-detection pipelines (MMF1, MMF3, PwS) that use a GNFW cluster model to extract the SZ signal, and is validated through extensive cross-matching with X-ray and optical clusters and a dedicated Monte Carlo quality assessment to characterize completeness and reliability. The outputs include refined SZ measurements, an SZ–X-ray scaling framework, and a mass proxy enabling cosmological analyses, making the PSZ a cornerstone resource for multi-wavelength cluster studies and future SZ-based cosmology.

Abstract

We describe the all-sky Planck catalogue of clusters and cluster candidates derived from Sunyaev--Zeldovich (SZ) effect detections using the first 15.5 months of Planck satellite observations. The catalogue contains 1227 entries, making it over six times the size of the Planck Early SZ (ESZ) sample and the largest SZ-selected catalogue to date. It contains 861 confirmed clusters, of which 178 have been confirmed as clusters, mostly through follow-up observations, and a further 683 are previously-known clusters. The remaining 366 have the status of cluster candidates, and we divide them into three classes according to the quality of evidence that they are likely to be true clusters. The Planck SZ catalogue is the deepest all-sky cluster catalogue, with redshifts up to about one, and spans the broadest cluster mass range from (0.1 to 1.6) 10^{15}Msun. Confirmation of cluster candidates through comparison with existing surveys or cluster catalogues is extensively described, as is the statistical characterization of the catalogue in terms of completeness and statistical reliability. The outputs of the validation process are provided as additional information. This gives, in particular, an ensemble of 813 cluster redshifts, and for all these Planck clusters we also include a mass estimated from a newly-proposed SZ-mass proxy. A refined measure of the SZ Compton parameter for the clusters with X-ray counter-parts is provided, as is an X-ray flux for all the Planck clusters not previously detected in X-ray surveys.

Figures (6)

• Figure 1: The Shapley super-cluster as seen in the Planck survey. Upper panel: reconstructed thermal SZ map $3.2^{\circ} \times 1.8^{\circ}$ from MILCAhur13. The dotted circles represent apertures of $\theta_{500}$ from the MCXC meta-catalogue around the resolved clusters. Lower panel: composite view of the optical from DSS images (white), X-rays from ROSAT (pink) survey and of the thermal SZ effect as seen in Planck (blue).
• Figure 2: Sky distribution of the 1227 Planck clusters and candidates (red dots), in a Mollweide projection with the Galactic plane horizontal and centred at longitude zero. Small grey dots show the positions of masked point sources, and grey shading shows the mask used to exclude the Magellanic clouds and the Galactic plane mask. The mask covers 16.3% of the sky.
• Figure 3: Noise maps per detection patch of MMF3 method measured for a 6$^{\prime}$ filter. The noise ranges from 0.5 to 2 times the average noise of the map, which is $\sigma_Y=2.4\times 10^{-4}$ arcmin$^2$. The Ecliptic polar regions, delimited by green contours, with increased redundancy in the observations define a deep survey zone covering in total 2.7% of the sky. It is less noisy than the areas near the Galactic plane, where the dust emission is higher. Two other zones are defined: a medium-deep survey zone of 41.3% coverage delimited by the red contours and with higher noise level; and a shallow-survey zone covering 56% of the sky and with the highest noise levels including regions near the Galactic plane.
• Figure 4: Illustration of the SZ size--flux degeneracy for two clusters detected by Planck. Right: Abell 2163 (S/N $=27$) and left: PSZ1 G266.6-27.3 (S/N $=6$ at $z\simeq 1$). The contours show the 68, 95, and 99 percent confidence levels.
• Figure 5: Distribution of the maximum likelihood SZ flux $Y_\mathrm{5R_{500}}$ and size $\theta_{500}$ for Planck SZ detections in the union catalogue down to S/N $=4.5$. Detections associated with known or new confirmed clusters are shown as open black circles. SZ cluster candidates are shown as filled red circles.