Gamma-Ray and Neutrino Emissions from Starforming and Starburst Galaxies

Abstract

Experimental observations have demonstrated a strong correlation between the star formation rate and the gamma-ray lumosities of starforming and starburst galaxies (SFGs and SBGs). However, the real origin of these emissions is still under debate. In this contribution, we present several updates on their non-thermal radiations, revisiting both their point-like and cumulative (diffuse) emission properties. From the point-like side, we discuss the potential- ities of future neutrino (KM3NeT/ARCA, IceCube-gen2) telescopes to quanti- tively scrutinize their expected properties from different cosmic-ray transport models. From the diffuse perspective, we investigate a model based on a data- driven blending of spectral indexes, hence taking into account the changes in the properties of individual emitters. Strikingly, SFGs and SBGs can explain 25% (up to 40%) of the diffuse High-Energy Starting Events (HESE) data, without overshooting the gamma-ray limits regarding non-blazar sources.