# Constraining the Rotational Kinematic Sunyaev-Zel'dovich Effect in Massive Galaxy Clusters

## TL;DR

This paper investigates the rotational kinematic Sunyaev-Zel'dovich effect in galaxy clusters using Planck and SDSS data, providing tentative evidence for the effect's presence and discussing future measurement prospects.

## Contribution

It introduces methods to constrain the rkSZ effect in galaxy clusters and presents the first tentative detection using CMB data and galaxy rotation vectors.

## Key findings

- Approximately 2σ evidence for the rkSZ signal
- Consistent amplitude and morphology with theoretical expectations
- Employs both model-dependent and less model-dependent measurement approaches

## Abstract

We constrain the rotational kinematic Sunyaev-Zel'dovich (rkSZ) effect in Planck data using a sample of rotating galaxy clusters identified in the Sloan Digital Sky Survey (SDSS). We extract cluster-centered cutouts from Planck cosmic microwave background (CMB) maps that have been cleaned of thermal SZ signal. Using previous constraints on the cluster rotation vectors determined from the motions of galaxies, we fit for the amplitude of the rkSZ effect in the CMB cutouts, marginalizing over parameters describing the cluster electron distribution. We also employ an alternative, less model-dependent approach to measuring the rkSZ signal that involves measuring the dipole induced by the rkSZ in rotation velocity-oriented CMB stacks. In both cases, we find roughly $2\sigma$ evidence for a rkSZ signal consistent with the expected amplitude and morphology. We comment on future directions for measurements of the rkSZ signal.