AGILE legacy archive follow-up of the exceptional Km3Net neutrino event Km3-230213A
ATel #17056; G. Panebianco, A. Bulgarelli (INAF/OAS-Bo), C. Pittori (SSDC and INAF/OAR), G. Piano, M. Cardillo (INAF/IAPS), N. Parmiggiani (INAF/OAS-Bo), P. W. Cattaneo (INFN Pavia), M. Tavani (INAF/IAPS and Univ. Roma Tor Vergata), R. Poggiani (Uni. di Pisa), F. Verrecchia, F. Lucarelli (SSDC and INAF/OAR), A. Giuliani (INAF/IASF-Mi), F. Longo (Univ. Trieste and INFN Trieste) and S. Vercellone (INAF/OA-Brera), on behalf of the AGILE Team
on 28 Feb 2025; 15:30 UT
Credential Certification: Andrea Bulgarelli (bulgarelli@iasfbo.inaf.it)
Subjects: Gamma Ray, >GeV, Neutrinos
Following the recent publication by the Km3NeT Collaboration of an extremely high-energy muon event detected on T0=2023-02-13 01:16:47 UT [1], which is most likely the product of a neutrino with estimated energy much larger than any previous detection, we searched for significant gamma-ray emission in the AGILE/GRID data legacy archive above 100 MeV consistent with the neutrino location: RA(J2000) = 94.3 deg, Dec(J2000) =-7.8 deg.No significant detection was obtained in 3, 7 and 14-day time intervals centred on T0.
We note that we have identified two telemetry data gaps near T0: on 2023-02-12 from 20:44 to 23:47 UT, and on 2023-02-13 from 00:37 to 01:17 UT (which includes T0). The event location was well exposed again starting from 13 sec after T0.
A preliminary maximum likelihood analysis yields the following 2-sigma upper limits on the flux above 100 MeV:
9.7e-07 ph/cm^2/s (3d),
8.3e-07 ph/cm^2/s (7d),
7.6e-07 ph/cm^2/s (14d).
Additional analysis of the AGILE archive data is in progress.
[1] The KM3NeT Collaboration, Nature 638, 376-382 (2025)
