http://arxiv.org/abs/1705.06665
We analyze the IceCube four-year neutrino data in search of a signal from the Fermi bubbles. No signal is found from the bubbles or from their dense shell, even when taking into account the softer background. This imposes a conservative $\xi_i<8\%$ upper limit on the cosmic-ray ion (CRI) acceleration efficiency, and an $\eta\equiv \xi_e/\xi_i \gtrsim0.006$ lower limit on the electron-to-ion ratio of acceleration efficiencies (at the $2\sigma$ confidence level). For typical $\xi_i$, a signal should surface once the number of IceCube neutrinos increases by $\sim$an order of magnitude, unless there is a $<$PeV cutoff on the CRI spectrum.
N. Sherf, U. Keshet and I. Gurwich
Fri, 19 May 17
62/62
Comments: 4 pages, 1 figure, 1 table; comments welcome