Oral Presentation
Unified weak lensing constraints on the M - Lx relation for galaxy clusters
Presenter: Isabel Pederneiras (University of São Paulo)
Scaling relations between galaxy cluster properties are crucial for understanding cosmology and baryonic physics. Calibrating the M–Lx relation with weak lensing masses and consistent statistical methods is challenging due to heterogeneous cluster samples. The release of LEGACY imaging data offers a path toward unifying cluster selection. We present the all-sky extension of the CODEX catalog based on LEGACY data and introduce a Bayesian framework to calibrate the X-ray luminosity–mass relation, using 100 clusters with weak lensing mass measurements. X-ray luminosities are derived from ROSAT All-Sky Survey (RASS) data, and we perform a power-law fit to the M–Lx relation. Additionally, using newly released eROSITA data (eRASS1), we assess point source contamination for 42 clusters within the eRASS1 footprint. The RASS fit yields a slope of β = 0.75 ± 0.09, which is 1.7σ lower than the self-similar prediction, with marginal evidence for redshift evolution (γ = 0.65 ± 0.43). In contrast, the eRASS1 analysis results in a steeper slope, β = 1.11 ± 0.15, in better agreement with self-similarity. No additional redshift evolution is also seen in this case (γ = 0.004 ± 0.790). While our results provide a practical basis for cosmological studies using both RASS and eRASS data, the connection to cluster physics becomes clearer once flux contamination is reduced. We also assess the impact of selection effects on the calibration and demonstrate that full modeling of the selection function is essential.
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