2 research outputs found
Solar Energetic Particle Spectrum on 13 December 2006 Determined by IceTop
On 13 December 2006 the IceTop air shower array at the South Pole detected a
major solar particle event. By numerically simulating the response of the
IceTop tanks, which are thick Cherenkov detectors with multiple thresholds
deployed at high altitude with no geomagnetic cut-off, we determined the
particle energy spectrum in the energy range 0.6 to 7.6 GeV. This is the first
such spectral measurement using a single instrument with a well defined viewing
direction. We compare the IceTop spectrum and its time evolution with
previously published results and outline plans for improved resolution of
future solar particle spectra.Comment: To appear in Astrophysical Journal Letters, 6 pages, 4 figure
The Search for Muon Neutrinos from Northern Hemisphere Gamma-Ray Bursts with AMANDA.
We present the results of the analysis of neutrino observations by the
Antarctic Muon and Neutrino Detector Array (AMANDA) correlated with photon
observations of more than 400 gamma-ray bursts (GRBs) in the Northern
Hemisphere from 1997 to 2003. During this time period, AMANDA's effective
collection area for muon neutrinos was larger than that of any other existing
detector. Based on our observations of zero neutrinos during and immediately
prior to the GRBs in the dataset, we set the most stringent upper limit on muon
neutrino emission correlated with gamma-ray bursts. Assuming a Waxman-Bahcall
spectrum and incorporating all systematic uncertainties, our flux upper limit
has a normalization at 1 PeV of
E^2{\Phi}_{\nu} {\leq} 6.0 \times 10^{-9} GeV cm^{-2} s^{-1} sr^{-1}, with
90% of the events expected within the energy range of ~10 TeV to ~3 PeV. The
impact of this limit on several theoretical models of GRBs is discussed, as
well as the future potential for detection of GRBs by next generation neutrino
telescopes. Finally, we briefly describe several modifications to this analysis
in order to apply it to other types of transient point sources.Comment: 44 pages, 10 figures; submitted to Astrophysical Journa