Search for time-independent neutrino emission from astrophysical sources with 3 yr of IceCube data
- School of Chemistry and Physics, University of Adelaide, Adelaide SA 5005 (Australia)
- Department of Physics and Wisconsin IceCube Particle Astrophysics Center, University of Wisconsin, Madison, WI 53706 (United States)
- Department of Physics and Astronomy, University of Gent, B-9000 Gent (Belgium)
- DESY, D-15735 Zeuthen (Germany)
- Department of Physics and Astronomy, University of Canterbury, Private Bag 4800, Christchurch (New Zealand)
- Département de physique nucléaire et corpusculaire, Université de Genève, CH-1211 Genève (Switzerland)
- Institut für Physik, Humboldt-Universität zu Berlin, D-12489 Berlin (Germany)
- Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States)
- Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States)
- Institute of Physics, University of Mainz, Staudinger Weg 7, D-55099 Mainz (Germany)
- Department of Physics, University of California, Berkeley, CA 94720 (United States)
- Department of Physics and Center for Cosmology and Astro-Particle Physics, Ohio State University, Columbus, OH 43210 (United States)
- Université Libre de Bruxelles, Science Faculty CP230, B-1050 Brussels (Belgium)
- Fakultät für Physik and Astronomie, Ruhr-Universität Bochum, D-44780 Bochum (Germany)
- Department of Physics, University of Wuppertal, D-42119 Wuppertal (Germany)
We present the results of a search for neutrino point sources using the IceCube data collected between 2008 April and 2011 May with three partially completed configurations of the detector: the 40-, 59-, and 79-string configurations. The live-time of this data set is 1040 days. An unbinned maximum likelihood ratio test was used to search for an excess of neutrinos above the atmospheric background at any given direction in the sky. By adding two more years of data with improved event selection and reconstruction techniques, the sensitivity was improved by a factor of 3.5 or more with respect to the previously published results obtained with the 40-string configuration of IceCube. We performed an all-sky survey and a dedicated search using a catalog of a priori selected objects observed by other telescopes. In both searches, the data are compatible with the background-only hypothesis. In the absence of evidence for a signal, we set upper limits on the flux of muon neutrinos. For an E {sup –2} neutrino spectrum, the observed limits are (0.9-5) × 10{sup –12} TeV{sup –1} cm{sup –2} s{sup –1} for energies between 1 TeV and 1 PeV in the northern sky and (0.9-23.2) × 10{sup –12} TeV{sup –1} cm{sup –2} s{sup –1} for energies between 10{sup 2} TeV and 10{sup 2} PeV in the southern sky. We also report upper limits for neutrino emission from groups of sources that were selected according to theoretical models or observational parameters and analyzed with a stacking approach. Some of the limits presented already reach the level necessary to quantitatively test current models of neutrino emission.
- OSTI ID:
- 22348409
- Journal Information:
- Astrophysical Journal, Vol. 779, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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