Search for point-like sources of ultra-high energy neutrinos at the Pierre Auger Observatory and improved limit on the diffuse flux of tau neutrinos

THE PIERRE AUGER COLABORATION; C. JARNE

Astrophysical Journal Letters

IOP Publishing c/o AIP

Año: 2012

2041-8205

The Surface Detector array of the Pierre Auger Observatory can detect neutrinos with energy E between 1017 eV and 1020 eV from point-like sources across the sky south of +55◦ and north of −65◦ declinations. A search has been performed for highly inclined extensive air showers produced by the interaction of neutrinos of all flavours in the atmosphere (downward-going neutrinos), and by the decay of tau leptons originating from tau neutrinos interactions in the Earth?s crust (Earth-skimming neutrinos). No candidate neutrinos have been found in data up to 2010 May 31. This corresponds to an equivalent exposure of 3.5 years of a full surface detector array for the Earth-skimming channel and 2 years for the downward-going channel. An improved upper limit on the diffuse flux of tau neutrinos has been derived. Upper limits on the neutrino flux from pointlike sources have been derived as a function of the source declination. Assuming a differential neutrino flux kPS · E−2  from a point-like source, 90% C.L. upper limits for kPS at the level of  5×10−7 and 2.5×10−6 GeV cm−2 s−1 have been obtained over a broad range of declinations from the searches of Earth-skimming and downward-going neutrinos, respectively.