Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Metals in the Universe and Diffuse Background Radiation   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.

27
The categories of this paper are: comp-gas
30
The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
8
The categories of this paper are: hep-ex
14
The categories of this paper are: math-ph
0
The categories of this paper are: hep-ph
3
The categories of this paper are: physics
36
The categories of this paper are: cmp-lg
19
The categories of this paper are: eess
28
The categories of this paper are: alg-geom
15
The categories of this paper are: nucl-ex
22
The categories of this paper are: chao-dyn
37
The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci
1
The categories of this paper are: cs