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Abstract The electron antineutrino flux limits are presented for the brightest gamma-ray burst (GRB) of all time, GRB221009A, over a range of 1.8–200 MeV using the Kamioka Liquid Scintillator Antineutrino Detector. Using multiple time windows ranging from minutes to days surrounding the event to search for electron antineutrinos coincident with the GRB, we set an upper limit on the flux under the assumption of several power-law neutrino source spectra, with power-law indices ranging from 1.5 to 3 in steps of 0.5. No excess was observed in any time windows ranging from seconds to days around the event trigger timeT0. For a power-law index of 2 and a time window ofT0 ± 500 s, a flux upper limit of 2.34 × 109cm−2was calculated. The limits are compared to the results presented by IceCube.
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This content will become publicly available on January 13, 2027
First Associated Neutrino Search for a Failed Supernova Candidate with Super-Kamiokande
Abstract In 2024, a failed supernova (SN) candidate, M31-2014-DS1, was reported in the Andromeda galaxy (M31), located at a distance of approximately 770 kpc. In this Letter, we search for neutrinos from this failed SN using data from Super-Kamiokande (SK). Based on the estimated time of black hole formation inferred from optical and infrared observations, we define a search window for neutrino events in the SK data. Using this window, we develop a dedicated analysis method for failed SNe and apply it to M31-2014-DS1, by conducting a cluster search using the timing and energy information of candidate events. No significant neutrino excess is observed within the search region. Consequently, we place an upper limit on the time-integrated electron antineutrino luminosity from M31-2014-DS1 and discuss its implications for various failed SN models and their neutrino emission characteristics. Despite the 18 MeV threshold adopted to suppress backgrounds, the search remains sufficiently sensitive to constrain the Shen-TM1 equation of state, in a more optimistic emission scenario with progenitor stars of 40M⊙and relatively high mean electron-antineutrino energies of about 23.2 MeV, yielding a 90% confidence level upper limit of 1.76 × 1053erg on the time-integrated electron antineutrino luminosity, moderately above the expected value of 1.35 × 1053erg.
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- Award ID(s):
- 2411709
- PAR ID:
- 10689863
- Author(s) / Creator(s):
- ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more »
- Publisher / Repository:
- The Astrophysical Journal Letters 997:L9 (9pp), 2026 January 20
- Date Published:
- Journal Name:
- The Astrophysical Journal Letters
- Volume:
- 997
- Issue:
- 1
- ISSN:
- 2041-8205
- Page Range / eLocation ID:
- L9
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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