BLOX: The Bonn Lensing, Optical, and X-ray selected galaxy clusters -- I. Cluster catalog construction

TL;DR

This paper presents a new catalog of 155 galaxy cluster candidates identified through optical, X-ray, and weak lensing methods, providing a valuable resource for studying selection biases in cluster detection.

Contribution

The study develops and tests new weak-lensing search criteria, combines multiple detection methods, and creates a comprehensive cluster catalog from the XMM-Newton survey data.

Findings

Shape noise dominates the survey's noise sources.

Spurious detections from large-scale structures are minimal.

Most cluster candidates are newly identified.

Abstract

The mass function of galaxy clusters is an important cosmological probe. Differences in the selection method could potentially lead to biases when determining the mass function. From the optical and X-ray data of the XMM-Newton Follow-Up Survey, we obtained a sample of galaxy cluster candidates using weak gravitational lensing, the optical Postman matched filter method, and a search for extended X-ray sources. We developed our weak-lensing search criteria by testing the performance of the aperture mass statistic on realistic ray-tracing simulations matching our survey parameters and by comparing two filter functions. We find that the dominant noise source for our survey is shape noise at almost all significance levels and that spurious cluster detections due to projections of large-scale structures are negligible, except possibly for highly significantly detected peaks. Our full cluster catalog has 155 cluster candidates, 116 found with the Postman matched filter, 59 extended X-ray sources, and 31 shear selected potential clusters. Most of these cluster candidates were not previously known. The present catalog will be a solid foundation for studying possible selection effects in either method.