Metals in the Universe and Diffuse Background Radiation

Abstract

An attempt is made to guess the overall cosmic abundance of `metals' and the contribution made by the energy released in their production to the total intensity of extragalactic background light (EBL). With a comparable or somewhat larger amount coming from white dwarfs, and a probably quite modest contribution from AGNs, one can fairly easily account for the lower end of the range of existing estimates for the total EBL intensity (50to 60 nwt m$^{-2}$ sterad$^{-1}$), but it seems more difficult should some higher estimates (90 to 100 in the same units) prove to be correct.

10 pages, 3 postscript figures To be published in: Vulcano Workshop: Chemical Enrichment of Intracluster and Intergalactic Medium, May 14 - 18 2001, eds. F. Matteucci and F. Giovannelli, ASP Conference Series