Ultraviolet Background Radiation Around Galaxy Clusters
Abstract
The diffuse ultraviolet background radiation has been mapped over most of the sky using data from the GALEX survey by Murthy 2014. We take advantage of this map to study the correlation between the UV background and clusters of galaxies discovered via the Sunyaev-Zeldovich effect in the Planck survey (Planck Collaboration 2015). We use only high galactic latitude (|b| > 60 o ) galaxy clusters to avoid contamination by galactic foregrounds, and we only analyze clusters with a measured redshift. This leaves us with a sample of ~185 clusters over the redshift range 0.02 z 0.89.In analysing our stacked sample, we find a statistically significant excess of UV background radiation over the average measured around random blank fields. We measure the stacked radial profile of these clusters, and find that the excess UV radiation decays to the level of the background at a radius roughly consistent with the maximum radial extent of the clusters. While the coarse 2' resolution of the diffuse background maps used prevents more detailed analysis of the substructure of the cluster contribution to the background radiation, the presence of this excess diffuse UV radiation around galaxy clusters provides an intriguing new contributor to the ultraviolet background. Support for this work was provided by NASA to the Johns Hopkins University through APRA grant NNX17AC26G.
- Publication:
-
American Astronomical Society Meeting Abstracts #233
- Pub Date:
- January 2019
- Bibcode:
- 2019AAS...23326102W