On 3/8/10 3:13 PM, Robert L. Oldershaw wrote:

The Fermi team reports ( http://arxiv.org/PS_cache/arxiv/pdf/...002.4415v1.pdf
) that only about 1/3 of the diffuse Gamma-ray background comes from
active galaxies. That leaves 2/3 of the background being produced by
unknown entities.


A large question is whether the peak at 56 Mev (figure 4)
EGRET (Sreekumar et al. 1997)
EGRET (Strong et al. 2004)

is confirmed by further data analysis extending
Fermi (Abdo et al. 2009) (figure 4)
to that 56 Mev peak range.

Why the peak?
and
why the near constant log slope with increased energy?

This is a 'noisy' area of the FERMI platform and will take more data
analysis time.

I think the answer is extremely fundamental.

Richard D. Saam