KIPAC Tea Talk: No Cluster Left Behind: Multiwavelength Cluster Analysis with All the Data

Abstract: Cluster abundance is among the most powerful cosmological probes, but its constraining power is currently limited by systematic uncertainties in mass calibration. Optically selected samples in particular suffer from line-of-sight projection effects that bias both richness and lensing measurements. Jointly modeling clusters observed across multiple wavelengths offers a path to self-calibrating these systematics ― yet previous multiwavelength analyses have typically discarded clusters lacking tSZ or X-ray counterparts, sacrificing much of the sample's statistical power. In this talk, I will present an analysis framework that retains every cluster detected in at least one survey: no cluster left behind. Applying it to Dark Energy Survey and South Pole Telescope data, I will show joint constraints on cluster mass calibration and optical projection effects. I will conclude by looking forward to multiwavelength cluster cosmology in the era of Rubin, Roman, SPT-3G, and eROSITA.