The 'fermi Line' (the 130 GEv gamma ray signal)

d3mm

http://arxiv.org/abs/1206.1616

Strong Evidence for Gamma-ray Line Emission from the Inner Galaxy - Meng Su, Douglas P. Finkbeiner

Analysis of data from the Fermi telescope shows "monochromatic" gamma ray emission at 130 GeV from the centre of the galaxy.

This paper is generating a lot of talk recently. What is the significance?

phyzguy

Some people think it may be produced by Dark Matter - Anti Dark Matter particle annihilation. If so it would be considered a direct detection of dark matter - that's why people are excited.

d3mm

Is this 130 GeV value predicted, or is it a case of "there is nothing else (it could be), so it must be"

edit: Couldn't this be a signal for SUSY as well as dark matter? Those would also be new particles.

Nabeshin

Yes but the idea is that in SUSY whatever supersymmetric particles you have should decay down to the LSP, which is the dark matter candidate. This is the only thing you expect to still be around since it can't decay, so it would be these particles annihilating.

Chalnoth

No, it's not possible to predict a specific value without knowing the mass and annihilation mechanisms, neither of which we can know until we know the particle that makes up dark matter.

That said, if dark matter frequently annihilates into a pair of photons, then we would expect to see a sharp peak in gamma ray output right at the mass of the dark matter particle.

I'm not sure there would be enough information in the signal to determine whether it's SUSY or some other model.