On Sunday, December 11, 2016 at 4:35:21 AM UTC-5, wrote=
:
I'm working to assemble a table / graph for the Luminosity of the
universe as a function of age of the universe.

I think these are the only sources of consequence (did I miss anything
important that I should include?):

1) CBR
2) Starlight (galaxies)
3) SN's
4) Active Galaxy nuclei

Thanks,

rt
One more, in addition to the hot IGM (a source of x-rays): galaxy-galaxy
interactions, e.g. collisions, flybys, mergers. Especially interactions
of (cold) gas-rich galaxies. These can, and do, trigger star-formation
(sometimes spectacularly so), SNs, and can also fire up (often
restart) AGNs. However, collisions of gas clouds can heat the gas
(and its dust), so generating a lot of IR.

PH is right, of course, to point out that dust is generally/often
heated by starlight, SNe, etc ... but not always.

Oh, and star-formation produces lots of photons, not all of them
from stars ...