# Environmental Effects on the UV Upturn in Local Clusters of Galaxies

## TL;DR

This study investigates whether the UV upturn in early type cluster galaxies depends on cluster environment or galaxy position, finding it to be an intrinsic property unaffected by external factors.

## Contribution

It demonstrates that the UV upturn phenomenon in early type galaxies is independent of cluster properties and galaxy location within clusters.

## Key findings

- UV upturn colours show no dependence on cluster velocity dispersion or X-ray luminosity.
- No correlation between UV upturn and galaxy position or kinematics within clusters.
- UV upturn is an intrinsic feature of early type galaxies, regardless of environment.

## Abstract

We explore the dependence of UV upturn colours in early type cluster galaxies on the properties of their parent clusters (such as velocity dispersion and X-ray luminosity) and on the positions and kinematics of galaxies within them. We use a sample of 24 nearby clusters with highly complete spectroscopy and optical/infrared data to select a suitable sample of red sequence galaxies, whose FUV and NUV magnitudes we measure from archival GALEX data. Our results show that the UV upturn colour has no dependence on cluster properties and has the same range in all clusters. There is also no dependence on the projected position within clusters or on line-of-sight velocity. Therefore, our conclusion is that the UV upturn phenomenon is an intrinsic feature of cluster early type galaxies, irrespective of their cluster environment.