Planck 2013 results. XXIX. Planck catalogue of Sunyaev-Zeldovich sources (1303.5089v2)

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.

• The paper presents a comprehensive SZ cluster catalogue with 1227 entries, including 861 confirmed clusters and 178 new confirmations.
• The methodology employs three detection algorithms (MMF1, MMF3, PwS) across six Planck channels to achieve an 84% detection purity.
• The catalogue supports astrophysical and cosmological studies by enabling robust cross-validation with X-ray and optical data and refining key cosmic parameters.

Analysis of the Planck 2013 Results: Sunyaev–Zeldovich Source Catalogue

The paper "Planck 2013 results. XXIX. The Planck catalogue of Sunyaev–Zeldovich sources" presents a comprehensive catalogue derived from Sunyaev–Zeldovich (SZ) effect detections using Planck satellite data over 15.5 months. This catalogue, the largest SZ-selected to that date, includes 1227 entries, with 861 confirmed clusters (178 newly confirmed) and 366 classified as candidates. This expansive compilation serves as a critical tool for both astrophysical and cosmological studies.

The Sunyaev–Zeldovich effect, pivotal for the physical characterization of galaxy clusters, offers a robust method for the detection of clusters across broad mass and redshift ranges. It provides an exceptional opportunity to explore the growth of cosmic structures and to probe cosmological parameters such as dark energy and the mass of neutrinos. The reliability of these detections and their robustness against contamination from galactic foregrounds are crucial for leveraging these data in scientific analysis.

Methodology and Detection

The paper deploys a multi-frequency detection technique across the six highest-frequency Planck channels (100 GHz to 857 GHz), optimizing the signal-to-noise ratio while mitigating contamination from point sources and Galactic emissions. Three independent detection methods—two implementations of the matched multi-filter algorithm (MMF1 and MMF3) and PowellSnakes (PwS)—were utilized to ensure a comprehensive and cross-validated catalogue. The detected SZ source catalogue is the union of these individual lists, prioritized by detection likelihood.

The methodology rigorously addresses the degeneracy between cluster size and SZ flux, an inherent challenge in extracting accurate cluster parameters from SZ data. The approach taken includes cross-validation with ancillary datasets and detailed simulations to estimate completeness and reliability, ultimately assuring an 84% purity for detections at S/N ≥ 4.5.

Validation and External References

Critical to the credibility of the catalogue is the validation against existing X-ray, optical, and SZ data, with significant reference to the ROSAT All Sky Survey (RASS) and Sloan Digital Sky Survey (SDSS). The identification process was methodical, cross-referencing with known clusters from X-ray/optical catalogues and consolidating through extensive follow-up observations. These efforts culminated in the successful identification and redshift estimation for 813 clusters, providing substantial new candidates for astrophysical paper.

Numerical Insights and Practical Implications

The cluster sample spans a mass range from $0.1 \times 10^{15} M_\odot$ to $1.6 \times 10^{15} M_\odot$ and redshifts up to about one. This broad range and high completeness are strategic for observational cosmology, particularly in constraining the cosmic matter density and other key cosmological parameters through clustering statistics and the galaxy cluster mass function.

In addition to fulfilling a crucial role in cosmological constraints, the catalogue facilitates comparative studies across wavelengths and can validate and refine cosmological simulations. The engagement with multi-wavelength follow-up observations enriches the dataset, ensuring that the identified clusters are robustly characterized in multiple observables.

Future Developments

This catalogue lays a groundwork for future development in both instrumentation and methodology, underscoring the potential for deeper SZ surveys with improved resolution and sensitivity. As the SZ effect is largely independent of redshift, future telescopic advancements and methodologies could significantly enhance the depth and reliability of SZ catalogues, broadening the horizon for cluster-based cosmological inference.

The Planck SZ sources are pivotal for upcoming space missions and ground-based observatories aiming to investigate dark energy dynamics and the growth of structure in the Universe. Thus, a continuous effort to refine SZ measurements and explore synergies with optical and X-ray surveys could markedly enhance our grasp of the cosmos.

Conclusion

The Planck 2013 SZ source catalogue advances the field of cosmic structure paper by providing comprehensive, validated data crucial for astrophysical research and cosmological parameter estimation. It exemplifies the potential of combining sophisticated detection algorithms with extensive cross-validation and follow-up efforts, setting a new standard for SZ catalogues and reinforcing the scientific capability to probe deeper into the Universe’s history and structure.