The Manticore-Local Cluster Catalogue: A Posterior Map of Massive Structures in the Nearby Universe

Abstract

We present a publicly available catalogue of massive structures in the nearby Universe, constructed from the Manticore-Local posterior ensemble, a Bayesian field-level reconstruction that infers the underlying dark matter distribution from 2M++ galaxies. We identify massive structures by clustering the central haloes inferred at z = 0 across the 80 posterior realizations, selecting at most one member per realization. These associations serve as probabilistic counterparts to individual massive clusters, each with robust posterior estimates of mass, position, and velocity. The fiducial catalogue contains 401 associations with ambiguity rates below 5%, and at least 20 member haloes across the posterior ensemble. We independently validate these systems through stacked \textit{Planck} thermal SZ measurements, which yield significant detections showing the expected mass trend, consistent with the established Y--M scaling relation. Many associations exhibit coherent evolutionary histories, meaning that their progenitor haloes across the posterior ensemble trace consistent merger pathways rather than diverging into unrelated assembly scenarios. Even with only z = 0 constraints, the inference narrows each system's possible assembly pathway: progenitor haloes at earlier times occupy Lagrangian volumes 2--5 times smaller than those of mass-matched haloes in unconstrained LCDM simulations, reflecting genuine information gain from the observational constraints. Cross-matches with X-ray catalogues reveal systematic mass-scale differences that align with known observational biases: Manticore-Local masses are typically 1.7 times ROSAT-based estimates but agree at unity with weak-lensing-calibrated eROSITA measurements. This illustrates the catalogue's potential to flag individual systems with significant mass discrepancies for targeted investigation.