'Dragons' of the Gamms-Ray Sky

Be sure to check this out!

http://www.sciencedaily.com/releases...0302162505.htm

It has long been assumed that the diffuse Gamma-Ray background was
dominated by active galaxies like blazars, quasars, Seyferts, etc.

Now comes a dramatic result from the Fermi team that appears to reject
that assumption, and leaves a very important question in its place.

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.

Two possible explanations for the unknown source population are as
follows.

[Mod. note: to save time and electrons, let me be the first to point
out that there are probably more than two in total -- mjh]

(1) The radiation could be generated by hypothetical annihilations of
hypothetical WIMPS (good luck with that one).

(2) Alternatively, contrary to current assumptions, there could be a
roughly isotropic distribution of stellar-mass black holes in the MWG
halo that emit very high energy jets of particles which, in turn,
generate Gamma-rays. In this scenario, all galactic haloes would
contribute to the Gamma-ray background too.

Note that a large populaton of stellar-mass black holes in more
quiescent states would be a nice candidate for the Long Duration Radio
Transients and the anomalous radio background discovered in the ARCADE
observations.

Perhaps nature is sending us many hints: X-ray Ridge discrete sources,
LDRTs, RRATs, Gamma-ray background, microlensing-detected MACHOs,
Gamma-ray burst sources, pulsars, quiescent neutron stars, compact
central objects in SN remnants?

One general class of stellar-mass ultracompact objects with masses
primarily in the 10^-4 to 2.0 solar mass range would explain quite a
number of enigmatic results.

RLO
www.amherst.edu/~rloldershaw