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 reconstruction of the local Universe from 2M++ galaxies. We identify massive structures by clustering central haloes at $z = 0$ across the 80 posterior realizations, selecting at most one member per realization. These $\textit{associations}$ serve as probabilistic counterparts to individual massive clusters, each with robust posterior estimates of mass, position, and velocity. The catalogue contains 225 associations with mean masses $\langle M_{200} \rangle > 10^{14}$ M$_{\odot}$ persisting in at least 50\% of realizations. We independently validate these systems through stacked \textit{Planck} thermal Sunyaev--Zel'dovich measurements, which yield significant detections ($>3\sigma$) with amplitudes following the expected $Y$--$M$ relation. Many associations exhibit coherent evolutionary histories: even with only $z = 0$ constraints, the inference narrows each system's possible assembly pathway, localizing progenitor configurations to volumes 2--5 times smaller than mass-matched haloes in unconstrained $\Lambda$CDM simulations. Cross-matches with X-ray catalogues reveal systematic mass-scale differences that align with known observational biases: \textsc{Manticore-Local} masses are typically twice ROSAT-based estimates but agree at unity with weak-lensing-calibrated eROSITA measurements. This demonstrates the catalogue's capability to diagnose systematics on an object-by-object basis. The resulting catalogue provides an observationally consistent map of massive structures in the local Universe, enabling direct cross-probe comparisons, hybrid analyses combining simulated and observed quantities, and systematic mass-scale studies.