@article{ad52a55f5c404bd49f526dd1c9c5c896,
title = "Search for steady point-like sources in the astrophysical muon neutrino flux with 8 years of IceCube data",
abstract = " The IceCube Collaboration has observed a high-energy astrophysical neutrino flux and recently found evidence for neutrino emission from the blazar TXS 0506+ 056. These results open a new window into the high-energy universe. However, the source or sources of most of the observed flux of astrophysical neutrinos remains uncertain. Here, a search for steady point-like neutrino sources is performed using an unbinned likelihood analysis. The method searches for a spatial accumulation of muon-neutrino events using the very high-statistics sample of about 497,000 neutrinos recorded by IceCube between 2009 and 2017. The median angular resolution is ∼ 1 ∘ at 1 TeV and improves to ∼ 0. 3 ∘ for neutrinos with an energy of 1 PeV. Compared to previous analyses, this search is optimized for point-like neutrino emission with the same flux-characteristics as the observed astrophysical muon-neutrino flux and introduces an improved event-reconstruction and parametrization of the background. The result is an improvement in sensitivity to the muon-neutrino flux compared to the previous analysis of ∼ 35 % assuming an E - 2 spectrum. The sensitivity on the muon-neutrino flux is at a level of E2dN/dE=3·10-13TeVcm-2s-1. No new evidence for neutrino sources is found in a full sky scan and in an a priori candidate source list that is motivated by gamma-ray observations. Furthermore, no significant excesses above background are found from populations of sub-threshold sources. The implications of the non-observation for potential source classes are discussed. ",
author = "{IceCube Collaboration https://icecube.wisc.edu/} and Aartsen, {M. G.} and M. Ackermann and J. Adams and Aguilar, {J. A.} and M. Ahlers and M. Ahrens and D. Altmann and K. Andeen and T. Anderson and I. Ansseau and G. Anton and C. Arg{\"u}elles and J. Auffenberg and S. Axani and P. Backes and H. Bagherpour and X. Bai and A. Barbano and Barron, {J. P.} and Barwick, {S. W.} and V. Baum and R. Bay and Beatty, {J. J.} and {Becker Tjus}, J. and Becker, {K. H.} and S. BenZvi and D. Berley and E. Bernardini and Besson, {D. Z.} and G. Binder and D. Bindig and E. Blaufuss and S. Blot and C. Bohm and M. B{\"o}rner and F. Bos and S. B{\"o}ser and O. Botner and E. Bourbeau and J. Bourbeau and F. Bradascio and J. Braun and Bretz, {H. P.} and S. Bron and J. Brostean-Kaiser and A. Burgman and Busse, {R. S.} and T. Carver and C. Chen and Cowen, {D. F.}",
note = "Funding Information: Acknowledgements The IceCube collaboration acknowledges the significant contributions to this manuscript from Ren{\'e} Reimann. The authors gratefully acknowledge the support from the following agencies and institutions: USA – U.S. National Science Foundation-Office of Polar Programs, U.S. National Science Foundation-Physics Division, Wisconsin Alumni Research Foundation, Center for High Throughput Computing (CHTC) at the University of Wisconsin-Madison, Open Science Grid (OSG), Extreme Science and Engineering Discovery Environment (XSEDE), U.S. Department of Energy-National Energy Research Scientific Computing Center, Particle astrophysics research computing center at the University of Maryland, Institute for Cyber-Enabled Research at Michigan State University, and Astropar-ticle physics computational facility at Marquette University; Belgium – Funds for Scientific Research (FRS-FNRS and FWO), FWO Odysseus and Big Science programmes, and Belgian Federal Science Policy Office (Belspo); Germany – Bundesministerium f{\"u}r Bildung und Forschung (BMBF), Deutsche Forschungsgemeinschaft (DFG), Helmholtz Alliance for Astroparticle Physics (HAP), Initiative and Networking Fund of the Helmholtz Association, Deutsches Elektro-nen Synchrotron (DESY), and High Performance Computing cluster of the RWTH Aachen; Sweden – Swedish Research Council, Swedish Polar Research Secretariat, Swedish National Infrastructure for Computing (SNIC), and Knut and Alice Wallenberg Foundation; Australia – Australian Research Council; Canada – Natural Sciences and Engineering Research Council of Canada, Calcul Qu{\'e}bec, Compute Ontario, Canada Foundation for Innovation, WestGrid, and Compute Canada; Denmark – Villum Fonden, Danish National Research Foundation (DNRF), Carlsberg Foundation; New Zealand – Marsden Japan – Japan Society for Promotion of Science (JSPS) and Institute for Global Prominent Research (IGPR) of Chiba University; Korea – National Research Foundation of Korea (NRF); Switzerland – Swiss National Science Foundation (SNSF). Publisher Copyright: {\textcopyright} 2019, The Author(s).",
year = "2019",
month = mar,
day = "1",
doi = "10.1140/epjc/s10052-019-6680-0",
language = "English (US)",
volume = "79",
journal = "European Physical Journal C",
issn = "1434-6044",
publisher = "Springer New York",
number = "3",
}