2016MNRAS.460.2875Y

Fast radio bursts (FRBs) are a mysterious flash phenomenon detected in radio wavelengths with a duration of only a few milliseconds, and they may also have prompted gamma-ray flashes. Here, we carry out a blind search for ms-duration gamma-ray flashes using the 7-yr Fermi Large Area Telescope all-sky gamma-ray data. About 100 flash candidates are detected, but after removing those associated with bright steady point sources, we find no flash events at high Galactic latitude region (|b| > 20deg). Events at lower latitude regions are consistent with statistical flukes originating from the diffuse gamma-ray background. From these results, we place an upper limit on the GeV gamma-ray to radio flux ratio of FRBs as ξ ≡ (νL_ν)γ/(νL_ν)radio <= (4.2-12) x 10^7, depending on the assumed FRB rate evolution index β=0-4 [cosmic FRB rate Φ_FRB ∝ (1 + z)^β]. This limit is comparable with the largest value found for pulsars, though ξ of pulsars is distributed in a wide range. We also compare this limit with the spectral energy distribution of the 2004 giant flare of the magnetar SGR 1806-20.