Lowering IceCube's energy threshold for point source searches in the Southern Sky

Authors
Aartsen, M. G.; Abraham, K.; Ackermann, M.; Adams, J.; Aguilar, J. A.; Golup, Geraldina Tamara; Wallace, A.; Wallraff, M.; Wandkowsky, N.; Weaver, Ch.; Wendt, C.; Westerhoff, S.; Whelan, B. J.; Whitehorn, N.; Wickmann, S.; Wiebe, K.; Wiebusch, C. H.; Wille, L.; Williams, D. R.; Wills, L.; Wissing, H.; Wolf, M.; Wood, T. R.; Woschnagg, K.; Xu, D. L.; Xu, X. W.; Xu, Y.; Yanez, J. P.; Yodh, G.; Yoshida, S.; Zoll, M.
Publication Year
2016
Language
English
Format
article
Status
Published version
Description
Observation of a point source of astrophysical neutrinos would be a "smoking gun" signature of a cosmic-ray accelerator. While IceCube has recently discovered a diffuse flux of astrophysical neutrinos, no localized point source has been observed. Previous IceCube searches for point sources in the southern sky were restricted by either an energy threshold above a few hundred TeV or poor neutrino angular resolution. Here we present a search for southern sky point sources with greatly improved sensitivities to neutrinos with energies below 100 TeV. By selecting charged-current ν μ interacting inside the detector, we reduce the atmospheric background while retaining efficiency for astrophysical neutrino-induced events reconstructed with sub-degree angular resolution. The new event sample covers three years of detector data and leads to a factor of 10 improvement in sensitivity to point sources emitting below 100 TeV in the southern sky. No statistically significant evidence of point sources was found, and upper limits are set on neutrino emission from individual sources. A posteriori analysis of the highest-energy (~100 TeV) starting event in the sample found that this event alone represents a 2.8σ deviation from the hypothesis that the data consists only of atmospheric background.
Fil: Aartsen, M. G.. University of Adelaide; Australia
Fil: Abraham, K.. Technische Universität München; Alemania
Fil: Ackermann, M.. Deutsches Elektronen-Synchrotron; Alemania
Fil: Adams, J.. University Of Canterbury; Nueva Zelanda
Fil: Aguilar, J. A.. Université Libre de Bruxelles; Bélgica
Fil: Golup, Geraldina Tamara. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina
Fil: Wallace, A.. University of Adelaide; Australia
Fil: Wallraff, M.. Rwth Aachen University; Alemania
Fil: Wandkowsky, N.. University of Wisconsin; Estados Unidos
Fil: Weaver, Ch.. University of Alberta; Canadá
Fil: Wendt, C.. University of Wisconsin; Estados Unidos
Fil: Westerhoff, S.. University of Wisconsin; Estados Unidos
Fil: Whelan, B. J.. University of Adelaide; Australia
Fil: Whitehorn, N.. University of California at Berkeley; Estados Unidos
Fil: Wickmann, S.. Rwth Aachen University; Alemania
Fil: Wiebe, K.. Johannes Gutenberg Universitat Mainz; Alemania
Fil: Wiebusch, C. H.. Rwth Aachen University; Alemania
Fil: Wille, L.. University of Wisconsin; Estados Unidos
Fil: Williams, D. R.. University of Alabama at Birmingahm; Estados Unidos
Fil: Wills, L.. Drexel University; Estados Unidos
Fil: Wissing, H.. University of Maryland; Estados Unidos
Fil: Wolf, M.. Stockholms Universitet; Suecia
Fil: Wood, T. R.. University of Alberta; Canadá
Fil: Woschnagg, K.. University of California at Berkeley; Estados Unidos
Fil: Xu, D. L.. University of Wisconsin; Estados Unidos
Fil: Xu, X. W.. Southern University; Estados Unidos
Fil: Xu, Y.. Stony Brook University; Estados Unidos
Fil: Yanez, J. P.. Deutsches Elektronen-Synchrotron; Alemania
Fil: Yodh, G.. University of California at Irvine; Estados Unidos
Fil: Yoshida, S.. Chiba University; Japón
Fil: Zoll, M.. Stockholms Universitet; Suecia
Subject
NEUTRINO ASTRONOMY
IceCube
Neutrino angular resolution
Astronomía
Ciencias Físicas
CIENCIAS NATURALES Y EXACTAS
Access level
Open access
License
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repository
CONICET Digital (CONICET)
Institution
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identifier
oai:ri.conicet.gov.ar:11336/63561