Extreme-ultraviolet emission in the Fornax Cluster of galaxies

We present studies of the extreme-ultraviolet (EUV) emission in the Fornax Cluster of galaxies, a relatively nearby well-studied cluster with X-ray-emitting cluster gas and a very large radio source. We examine both the large-scale (approximately the size of the X-ray-emitting cluster gas) and the small-scale (<1') emission. We find that this cluster has large-scale diffuse EUV emission. However, at the sensitivity level of the existing Extreme Ultraviolet Explorer (EUVE) data, this emission is entirely due to the low-energy tail of the X-ray-emitting gas. We have also examined small-scale structures in raw EUVE images of this cluster. We find that small-scale irregularities are present in all raw Deep Survey images as a result of small-scale detector effects. These effects can be removed by appropriate flat-fielding. After flat-fielding, the Fornax Cluster still shows a few significant regions of small-scale EUV enhancement. We find that these are emission from stars and galaxies in the field. We find that at existing levels of sensitivity, there is no excess EUV emission in the cluster on either large or small scales.