1ES 1028+511: Upper limits from a neutrino search with IceCube
ATel #18019; Sam Hori (University of Wisconsin-Madison), Justin Vandenbroucke (University of Wisconsin-Madison)
on 28 Aug 2026; 05:13 UT
Credential Certification: Justin Vandenbroucke (justin.vandenbroucke@wisc.edu)
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 extreme high-synchrotron-peaked BL Lac object, 1ES 1028+511, following the reports of a TeV gamma-ray flare from LHAASO (ATel #17938). We analyzed a time window of 30 days centered on the detection time reported by LHASSO (2026-07-15 09:28:48 UTC to 2026-08-14 09:28:48 UTC), during which IceCube was collecting good quality data.
We obtain a p-value of 1.0, consistent with the atmospheric background only hypothesis. We accordingly derive a time-integrated muon-neutrino flux upper limit for this source of E^2 dN/dE = 8.2e-2 cm^-2 at 90% confidence level, for an E^-2 power law. 90% of events IceCube would detect from a source at this declination with an E^-2 spectrum have energies between approximately 610 GeV and 270 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)
