Constraining the sources of high-energy neutrinos with multiple messengers [BEL-center:pheno]

by Matthias Vereecken (UCLouvain - CP3)

Tuesday 9 May 2023, 13:00 → 14:00 Europe/Brussels

E/3rd floor-E.349 - Seminar room (E.349) (Marc de Hemptinne (chemin du Cyclotron, 2, Louvain-la-Neuve))

In recent years, the IceCube Neutrino Observatory has identified several sources of high-energy neutrinos. However, it is not yet clear which source class provides the dominant contribution or whether there there are other sources contributing to the astrophysical neutrino flux observed by IceCube. One way to constrain such sources is to combine information from different astrophysical messengers. In this seminar, I will present two such studies which I performed during my PhD: one by using the diffuse extragalactic gamma-ray background and one by looking at information from gravitational waves.

In the first part, I discuss constraints on the neutrino sources coming from the observed level of the extragalactic gamma-ray background: it is lower than expected given the astrophysical neutrino flux observed by the IceCube Observatory. As such, the neutrino sources must somehow be hidden or obscured in gamma rays. Here, I discuss a model where this obscuration is due to high column densities of matter near the source.

In the second part, I discuss the current constraints on neutrino emission from binary black hole mergers. While traditionally no such emission was expected, the first detection of gravitational waves triggered the development of several models where this is possible. Here, I show the current constraints on such emission from direct searches as well as from the observed astrophysical neutrino flux and the inferred merger rate of binary black holes.

matthiasvereecken_multimessengerneutrino.pdf