BL Lacertae gamma-ray flare: Upper limits from a neutrino search with IceCube
ATel #16890; Sam Hori (University of Wisconsin-Madisoni, Anna Franckowiak (Ruhr-University Bochum), Marcos Santander (University of Alabama - Tuscaloosa), Justin Vandenbroucke (University of Wisconsin-Madison)
on 1 Nov 2024; 05:12 UT
Credential Certification: Justin Vandenbroucke (justin.vandenbroucke@wisc.edu)
Subjects: Neutrinos, Blazar
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 blazar BL Lacertae during its recent gamma-ray flare (ATel #16849, #16850, #16854, #16861). The search was performed using a time window of fifteen days (2024-09-29 12:00:00.0 UTC to 2024-10-14 12:00:00.0 UTC), during which IceCube was collecting good quality data. This time window includes the Fermi LAT-detected gamma-ray flare as well as observations from LHAASO, VERITAS, and MAGIC.
We find that the data are consistent with atmospheric background expectations, with a p-value of 1.0. We accordingly derive a time-integrated muon-neutrino flux upper limit for this source of E^2 dN/ dE = 6.6 x 10^-2 GeV cm^-2 at 90% CL, under the assumption of an E^-2 power law. The central 90% energy range of events IceCube would detect from a source at this declination with an E^-2 spectrum is approximately 600 GeV to 250 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.
