High-energy neutrinos from astrophysical accelerators of cosmic ray nuclei
(2007)
Anisotropy studies around the galactic centre at EeV energies with the Auger Observatory
Astroparticle Physics 27:4 (2007) 244-253
Abstract:
Data from the Pierre Auger Observatory are analyzed to search for anisotropies near the direction of the Galactic Centre at EeV energies. The exposure of the surface array in this part of the sky is already significantly larger than that of the fore-runner experiments. Our results do not support previous findings of localized excesses in the AGASA and SUGAR data. We set an upper bound on a point-like flux of cosmic rays arriving from the Galactic Centre which excludes several scenarios predicting sources of EeV neutrons from Sagittarius A. Also the events detected simultaneously by the surface and fluorescence detectors (the 'hybrid' data set), which have better pointing accuracy but are less numerous than those of the surface array alone, do not show any significant localized excess from this direction. © 2006 Elsevier B.V. All rights reserved.The intergalactic propagation of ultrahigh energy cosmic ray nuclei
Astropart.Phys. 27 (2007) 199-212
Limits on the high-energy gamma and neutrino fluxes from the SGR 1806-20 giant flare of 27 December 2004 with the AMANDA-II detector.
Phys Rev Lett 97:22 (2006) 221101
Abstract:
On 27 December 2004, a giant gamma flare from the Soft Gamma-Ray Repeater 1806-20 saturated many satellite gamma-ray detectors, being the brightest transient event ever observed in the Galaxy. AMANDA-II was used to search for down-going muons indicative of high-energy gammas and/or neutrinos from this object. The data revealed no significant signal, so upper limits (at 90% C.L.) on the normalization constant were set: 0.05(0.5) TeV-1 m;{-2} s;{-1} for gamma=-1.47 (-2) in the gamma flux and 0.4(6.1) TeV-1 m;{-2} s;{-1} for gamma=-1.47 (-2) in the high-energy neutrino flux.Einstein's Universe: The Challenge of Dark Energy
Chapter in The Legacy of Albert Einstein, World Scientific Publishing (2006) 207-224