par Aguilar Sanchez, Juan Antonio ;Baker, Michael;Dumm, Jon;Montaruli, Teresa;Kurahashi, Naoko
Référence International Cosmic Ray Conference(32: 11 August 2011 through 18 August 2011: Beijing), Proceedings of the 32nd International Cosmic Ray Conference, ICRC 2011, Institute of High Energy Physics, Beijing, Vol. 8, page (101-104)
Publication Publié, 2011
Publication dans des actes
Résumé : We present the results of time-independent searches for astrophysical neutrino sources performed over the whole sky using data collected between April 2008 and May 2010 with the 40-string and 59-string configurations of the IceCube Neutrino Observatory. Muon tracks arriving in the detector from neutrino interactions are reconstructed using the time and charge information detected by an array of photomultiplier tubes (PMTs). In the northern sky, the data sample consists of 14,121 events collected with 40 strings and 43,339 with 59 strings, mostly muons induced by atmospheric neutrinos. In this sky region the search is sensitive to point sources of neutrinos with E-2 spectra mainly in the TeV-PeV energy range. In the opposite hemisphere, a much larger background of high-energy atmospheric muons dominate the data set. A zenith dependent energy cut is used to reduce the number of background events. This weakens the sensitivity for point sources with E-2 spectra with respect to the upgoing region. The downgoing region is more sensitive to harderspectrum sources for which the bulk of events can be detected between PeV-EeV energies. An unbinned maximum likelihood ratio test is used to search for astrophysical signals. For the first time it was adapted to combine data from different detector configurations. The combined sensitivity is about a factor ∼ 2.5 better than the previous 1-year limit of the 40-string configuration alone. A dedicated search based on a catalog of sources is also presented.

Documents en relation

DI-fusion