Far Ultraviolet Spectroscopic Explorer Limits on Far-Ultraviolet Emission from Warm Gas in Clusters of Galaxies
We have obtained far-ultraviolet spectra of two clusters of galaxies with the Far Ultraviolet Spectroscopic Explorer. The Coma Cluster was observed for a total of 28.6 ks, the Virgo Cluster for 10.9 ks. Neither spectrum shows significant O VI λλ1032, 1038 emission at the cluster redshift. Such emission would be expected from the warm [(5-10)×105 K] component of the intracluster medium that has been proposed to explain the excess EUV and soft X-ray flux present in EUVE and ROSAT observations of these clusters. Our 2 σ upper limits on the O VI λ1032 flux from Coma and Virgo exclude all published warm gas models of the EUV excess in these clusters. Based on observations made with the NASA-CNES-CSA FUSE, which is operated for NASA by Johns Hopkins University under NASA contract NAS5-32985.
The Astrophysical Journal
- Pub Date:
- March 2001
- Galaxies: Clusters: General;
- Ultraviolet: Galaxies;
- To appear in the Astrophysical Journal (Letters). 8 pages, including 1 table and 3 figures