Galactic Haze

The Planck Cosmic Microwave Background satellite telescope has verified that there really is a haze of higher energy photons than expected. They infer a spectrum of electrons that falls with energy as 1/E^2.1, which is quite a bit harder than the run-of-the-mill supernova shock electron spectrum which falls as 1/E^3.1 . I love hearing about the kind of work in which supernovas are ordinary background.

Pavel Naselsky is quoted as saying "The radiation has a spectrum which has the same form as that of synchrotron emission, which originates from electrons and positrons circulating at high energies around the lines of the Magnetic Field in the center of the galaxy, and I believe that there are quite strong indications that it could come from dark matter." I think he has in the back of his mind the 130GeV spike in the spectrum found by another experiment (but not verified; quite a few groups are looking), because I don't quite see how the Planck results suggest anything like dark matter.

If dark matter could annihilate with other dark matter to produce electrons, you would get a lot of high energy electrons curving in the galactic magnetic field, emitting relatively high energy photons as they go. So they're consistent with one model of dark matter, but that's not exactly evidence.

Something is certainly different about what is going on in the "bubbles", and the paper is worth looking at if only for the pictures of the bubbles above and below the galactic core. I'm afraid my eyes started to glaze over while skimming the discussion of all the different models being compared to the data. That's a vital part of their research, and similar things are critical in my field also, but vital doesn't make it exciting.

FWIW, the primary cosmic ray spectrum looks like 1/E^2.6 at the high end (Auger), so maybe it isn't dark matter but some similar acceleration processes at work. That would get my vote.

In the meantime, we have a shining haze where nobody expected it.