Metals in the Universe and diffuse background radiation

As was mentioned in Section 12.1, there is a relationship between metal production and diffuse background radiation, perhaps more properly referred to as extragalac-tic background light (EBL), shown in Fig. 12.1, since most or all of it comes from individual galaxies. 

Gispert, Lagache Puget (2000) have estimated the total EBL based on observation to lie within the following limits  

Cosmic chemical evolution and diffuse background radiation 

The result of these simple considerations is thus to account for about 55 nwtm-2 ster-1, much the same as in the model by Pei, Fall and Hauser it is striking to find the major contribution coming from white dwarfs. AGNs may account for another 5 or so nwtm-2 ster-1, so that the minimal estimate of EBL is more or less accounted for by the distribution of the elements. If the true EBL intensity were closer to the maximal estimates, then there would appear to be a shortfall and one might need to search for more exotic explanations, but at the time of writing that seems less likely. 

Excellent introductions to cosmology, galaxy surveys, theories of structure formation and background radiation can be found in 

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