How should we explore the origin of astrophysical high-energy neutrinos using multi-messenger data?
Speaker: Wataru Iwakiri (ICEHAP, Chiba University)
Abstract:
Astrophysical high-energy neutrinos (HENs) are valuable tools for tracing the origins of high-energy cosmic rays. In the 2010s, the IceCube Neutrino Observatory, which has 5160 PMT detectors buried in the 1450-2450 m depth of the South Pole, enabled us to detect HENs above 100 TeV, allowing us to observe this new messenger. So far, the IceCube team has identified three objects as HEN sources: the TeV blazar TXS 0506+056, the Seyfert II galaxy NGC 1068, and a galactic plane. However, the primary source of the diffuse flux of astrophysical HENs observed by IceCube remains unclear. Correlation analyses of several years of accumulated data indicate that observed gamma-ray blazars contribute to less than 20% of the diffuse flux at most. Furthermore, observed HENs show no significant correlation with gamma-ray bursts and account for less than 0.4% of the diffuse flux. In this talk, I will discuss potential candidates for astrophysical HEN sources and how to reveal them using multi-messenger approaches.