Search for steady point-like sources in the astrophysical muon neutrino flux with 8 years of IceCube data
Name
10052_2019_Article_6680.pdf
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3.12 MB
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Author(s)
Aartsen, M. G
Ackermann, M.
Adams, J.
Aguilar, J. A
Ahlers, M.
Ahrens, M.
Altmann, D.
Andeen, K.
Anderson, T.
Ansseau, I.
Date Issued
March 2019
Journal
The European Physical Journal C
Publisher
Springer Berlin Heidelberg
Version
Final published version
Abstract
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
$$\sim 1^\circ $$
∼
1
∘
at 1 TeV and improves to
$$\sim 0.3^\circ $$
∼
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
$$\sim 35\%$$
∼
35
%
assuming an
$$E^{-2}$$
E
-
2
spectrum. The sensitivity on the muon-neutrino flux is at a level of
$$E^2 \mathrm {d} N /\mathrm {d} E = 3\cdot 10^{-13}\,\mathrm {TeV}\,\mathrm {cm}^{-2}\,\mathrm {s}^{-1}$$
E
2
d
N
/
d
E
=
3
·
10
-
13
TeV
cm
-
2
s
-
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.
MIT Department
Massachusetts Institute of Technology. Department of Physics
Massachusetts Institute of Technology. Department of Physics
Terms of Use
Creative Commons Attribution 4.0 International license
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1140/epjc/s10052-019-6680-0
