TeV-PeV Neutrinos from Giant Flares of Magnetars and the Case of SGR 1806-20

We estimate the high energy neutrino flux from the giant flare of SGR 180620 on December 27, 2004, which irradiated Earth with a gamma-ray flux ∼ 10 times larger than the most luminous gamma-ray bursts (GRBs) ever detected. The Antarctic Cherenkov neutrino detector AMANDA was on-line during the flare, and may either have detected high energy neutrinos for the first time from a cosmic point source, or put constraints on the flare mechanism of magnetars. If TeV neutrinos are detected, one would expect also detectable EeV cosmic rays and possibly TeV gamma-ray emission in coincidence. Subject headings: cosmic rays — gamma rays: bursts — gamma rays: theory — stars: individual (SGR1806-20) — stars: neutron