Abstract
This Letter presents the results from pointlike neutrino source searches using ten years of IceCube data collected between April 6, 2008 and July 10, 2018. We evaluate the significance of an astrophysical signal from a pointlike source looking for an excess of clustered neutrino events with energies typically above among the background of atmospheric muons and neutrinos. We perform a full-sky scan, a search within a selected source catalog, a catalog population study, and three stacked Galactic catalog searches. The most significant point in the northern hemisphere from scanning the sky is coincident with the Seyfert II galaxy NGC 1068, which was included in the source catalog search. The excess at the coordinates of NGC 1068 is inconsistent with background expectations at the level of after accounting for statistical trials from the entire catalog. The combination of this result along with excesses observed at the coordinates of three other sources, including TXS , suggests that, collectively, correlations with sources in the northern catalog are inconsistent with background at significance. The southern catalog is consistent with background. These results, all based on searches for a cumulative neutrino signal integrated over the 10 years of available data, motivate further study of these and similar sources, including time-dependent analyses, multimessenger correlations, and the possibility of stronger evidence with coming upgrades to the detector.
- Received 18 October 2019
- Revised 13 December 2019
- Accepted 6 January 2020
DOI:https://doi.org/10.1103/PhysRevLett.124.051103
© 2020 American Physical Society
Physics Subject Headings (PhySH)
Synopsis
Possible Neutrino Sources Peek out of IceCube Data
Published 6 February 2020
Ten years of observations from the IceCube detector show that researchers are closing in on identifying the astrophysical sources of high-energy neutrinos.
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