Orateur
Description
We report a high-precision detection of the cross-correlation of the thermal Sunyaev-Zel'dovich (tSZ) effect and gravitational lensing of the cosmic microwave background (CMB) using data from the Planck 2018 legacy release. This is only the second reported detection of this cross-correlation to date, following early work using the Planck nominal mission data (Hill & Spergel 2014). In our analysis, we first construct component-separated tSZ maps from Planck data using a custom needlet internal linear combination (NILC) pipeline. We then cross-correlate our tSZ maps with publicly available Planck CMB lensing maps. We implement a novel moment-based approach to mitigate cosmic infrared background (CIB) contamination in our NILC tSZ maps. We validate our full analysis pipeline using detailed mm-wave sky simulations from the WebSky suite. We interpret our measurement of the tSZ -- CMB lensing cross-correlation using halo model calculations. We derive constraints on cosmological parameters ($S_8$, $\Omega_m$) and on parameters describing gas physics in the intracluster medium (ICM), for which our measurement probes the poorly explored regime of low-mass, high-redshift groups and clusters.
