LS V +44 17: Upper limits from a neutrino search with IceCube

ATel #18100; Alicia Mand (University of Wisconsin-Madison), Anna Franckowiak (Ruhr-University Bochum) for the IceCube Collaboration
on 10 Oct 2026; 21:01 UT
Credential Certification: Anna Franckowiak (anna.franckowiak@desy.de)

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The IceCube Collaboration (http://icecube.wisc.edu/) reports:

IceCube has performed a search for track-like muon neutrino events arriving from the direction of the Be/X-ray binary pulsar LS V +44 17 following reports of X-ray brightening and outbursts by EP-WXT (ATel #18063), Fermi GBM (ATel #18067), MAXI/GSC (ATel #18071), and XSPECT (ATel #18089). We adopted a time window of 25 days to cover the reported enhanced emission in X-rays (2026-09-13 12:00:00.00 UTC to 2026-10-08 12:00:00.00), during which IceCube was collecting good quality data.

For this search, we report a p-value of 1.0 with respect to an atmospheric background-only hypothesis. We accordingly derive a time-integrated muon-neutrino flux upper limit of E^2 dN/dE = 7.9e-2 GeV cm^-2 at 90% CL, for an E^-2 power law. 90% of events IceCube would detect from a source at this declination with an E^-2 spectrum are between approximately 650 GeV and 300 TeV.

The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector operating at the geographic South Pole, Antarctica. The IceCube realtime alert point of contact can be reached at roc@icecube.wisc.edu.

[1] IceCube Collaboration, R. Abbasi et al., ApJ 910 4 (2021)