Constraints on Galactic Neutrino Emission with Seven Years of IceCube Data

The origins of high-energy astrophysical neutrinos remain a mystery despite extensive searches for their sources. We present constraints from seven years of IceCube Neutrino Observatory muon data on the neutrino flux coming from the Galactic plane. This flux is expected from cosmic-ray interactions...

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Bibliographic Details
Main Authors: IceCube Collaboration, Arguelles Delgado, Carlos A, Axani, Spencer Nicholas, Collin, G. H., Conrad, Janet Marie, Moulai, Marjon H.
Other Authors: Massachusetts Institute of Technology. Department of Physics
Format: Article
Published: American Astronomical Society 2019
Online Access:http://hdl.handle.net/1721.1/120957
https://orcid.org/0000-0003-4186-4182
https://orcid.org/0000-0001-8866-3826
https://orcid.org/0000-0002-6393-0438
https://orcid.org/0000-0001-7909-5812
Description
Summary:The origins of high-energy astrophysical neutrinos remain a mystery despite extensive searches for their sources. We present constraints from seven years of IceCube Neutrino Observatory muon data on the neutrino flux coming from the Galactic plane. This flux is expected from cosmic-ray interactions with the interstellar medium or near localized sources. Two methods were developed to test for a spatially extended flux from the entire plane, both of which are maximum likelihood fits but with different signal and background modeling techniques. We consider three templates for Galactic neutrino emission based primarily on gamma-ray observations and models that cover a wide range of possibilities. Based on these templates and in the benchmark case of an unbroken E [superscript -2.5] power-law energy spectrum, we set 90% confidence level upper limits, constraining the possible Galactic contribution to the diffuse neutrino flux to be relatively small, less than 14% of the flux reported in Aartsen et al. above 1 TeV. A stacking method is also used to test catalogs of known high-energy Galactic gamma-ray sources.