High-energy neutrino production in clusters of galaxies

Abstract

Clusters of galaxies can potentially produce cosmic rays (CRs) up to very-high energies via large-scale shocks and turbulent acceleration. Due to their unique magnetic-field configuration, CRs with energy ≤1017 eV can be trapped within these structures over cosmological time scales, and generate secondary particles, including neutrinos and gamma rays, through interactions with the background gas and photons. In this work we compute the contribution from clusters of galaxies to the diffuse neutrino background. We employ three-dimensional cosmological magnetohydrodynamical simulations of structure formation to model the turbulent intergalactic medium. We use the distribution of clusters within this cosmological volume to extract the properties of this population, including mass, magnetic field, temperature, and density. We propagate CRs in this environment using multi-dimensional Monte Carlo simulations across different redshifts (from z ∼ 5 to z = 0), considering all relevant photohadronic, photonuclear, and hadronuclear interaction processes. We find that, for CRs injected with a spectral index α = 1.5 − 2.7 and cutoff energy Emax = 1016 − 5 × 1017 eV, clusters contribute to a sizeable fraction to the diffuse flux observed by the IceCube Neutrino Observatory, but most of the contribution comes from clusters with M ≳ 1014 M⊙ and redshift z ≲ 0.3. If we include the cosmological evolution of the CR sources, this flux can be even higher.

Particle Reacceleration by Turbulence and Radio Constraints on Multi-Messenger High-Energy Emission from the Coma Cluster

“…We see that the neutrino intensity for the secondarydominant model with α = 2.0 (left panel, thin solid) becomes 3 − 30% to the observed one, which is consistent with previous results on the typical accretion shock scenario (Murase et al 2008;Fang & Olinto 2016;Hussain et al 2021). Note that the neutrino luminosity function has not been considered in our estimate.…”

“…By including the cluster mass function and its redshift evolution as well as the CR distribution, the intensities can be further enhanced by a factor of ∼ O(1) − O(10), in which ∼ 100% of the IceCube intensity can be explained. For example, if CRPs are mainly injected from internal sources like AGNs, the redshift evolution of the source density can be as large as ξ z ∼ 3, instead of ξ z ∼ 1 (e.g., Fang & Murase 2018;Hussain et al 2021). The neutrino luminosity scales with L ν ∝ M 500 (that is different from the accretion shock scenario), the background intensity mainly originates from more clusters lighter than Coma .…”

“…The majority of IceCube neutrinos is still unknown, but such neutrinos should be produced by the hadronic interactions like pp or pγ collisions of relativistic protons. Many candidate sources have been proposed, including starburst galaxies (e.g., Loeb & Waxman 2006;Tamborra et al 2014;Senno et al 2015) and galaxy clusters (e.g., Berezinsky et al 1997;Murase et al 2008;Kotera et al 2009;Zandanel et al 2015;Fang & Olinto 2016;Hussain et al 2021).…”

“…The ratio between primary and secondary CREs in the seed population for the reacceleration was discussed in e.g., Brunetti et al (2017) and Pinzke et al (2017), but it is largely uncertain because of the parameter degeneracy in the reacceleration process. The diffusion of parent CRPs from primary accelerators has been of interest (e.g., Keshet & Loeb 2010;Keshet 2010), which has also been separately investigated in the calculation of high-energy emission or escaping CRs (e.g., Kotera et al 2009;Fang & Olinto 2016;Fang & Murase 2018;Hussain et al 2021).…”

Quantum gravity phenomenology at the dawn of the multi-messenger era -- A review

“…They can be considered as "closed boxes" that retain all their gaseous matter. Most of the cosmic rays produced in clusters of galaxies remain confined within the cluster and produce high-energy gamma rays and neutrinos [709,710] by interactions with the intracluster baryonic gas. A multi-messenger approach would provide insights to probe if galaxy clusters are sources of UHECRs.…”