1. Combined fit of spectrum and composition for FR0 radio-galaxy-emitted ultra–high energy cosmic rays with resulting secondary photons and neutrinosJon Paul Lundquist, Serguei Vorobiov, Lukas Merten, Anita Reimer, Margot Boughelilba, Paolo Da Vela, Fabrizio Tavecchio, Giacomo Bonnoli, Chiara Righi, 2025, original scientific article Abstract: This study comprehensively investigates the gamma-ray dim population of Fanaroff–Riley
Type 0 (FR0) radio galaxies as potentially significant sources of ultra–high energy cosmic rays
(UHECRs, E > 10[sup]18 eV) detected on Earth. While individual FR0 luminosities are relatively
low compared to the more powerful Fanaroff–Riley Type 1 and Type 2 galaxies, FR0s are
substantially more prevalent in the local universe, outnumbering the more energetic galaxies
by a factor of ∼5 within a redshift of z ≤ 0.05. Employing CRPropa3 simulations, we estimate
the mass composition and energy spectra of UHECRs originating from FR0 galaxies for energies
above 10[sup]18.6 eV. This estimation fits data from the Pierre Auger Observatory (Auger)
using three extensive air shower models; both constant and energy-dependent observed
elemental fractions are considered. The simulation integrates an approximately isotropic
distribution of FR0 galaxies, extrapolated from observed characteristics, with UHECR
propagation in the intergalactic medium, incorporating various plausible configurations of
extragalactic magnetic fields, both random and structured. We then compare the resulting
emission spectral indices, rigidity cutoffs, and elemental fractions with recent Auger results.
In total, 25 combined energy-spectrum and mass-composition fits are considered. Beyond
the cosmic-ray fluxes emitted by FR0 galaxies, this study predicts the secondary photon and
neutrino fluxes from UHECR interactions with intergalactic cosmic photon backgrounds.
The multimessenger approach, encompassing observational data and theoretical models,
helps elucidate the contribution of low-luminosity FR0 radio galaxies to the total cosmic-ray
energy density.
Keywords: ultra-high-energy cosmic rays, UHECRs, UHECR energy spectrum, Pierre Auger Observatory, UHECR mass composition, UHECR sources, extragalactic magnetic fields, UHECR propagation, CRPropa tool
Published in RUNG: 06.01.2025; Views: 215; Downloads: 6
 Full text (4,14 MB)
This document has many files! More... |
2. The UHECR-FR0 radio galaxy connection : a multi-messenger study of energy spectra/composition emission and intergalactic magnetic field propagationJon Paul Lundquist, Lukas Merten, Serguei Vorobiov, Margot Boughelilba, Anita Reimer, Paolo Da Vela, Fabrizio Tavecchio, Giacomo Bonnoli, Chiara Righi, 2023, published scientific conference contribution Abstract: This study investigates low luminosity Fanaroff-Riley Type 0 (FR0) radio galaxies as a potentially
significant source of ultra-high energy cosmic rays (UHECRs). Due to their much higher prevalence
in the local universe compared to more powerful radio galaxies (about five times more than
FR-1s), FR0s may provide a substantial fraction of the total UHECR energy density. To determine
the nucleon composition and energy spectrum of UHECRs emitted by FR0 sources, simulation
results from CRPropa3 are fit to Pierre Auger Observatory data. The resulting emission spectral
indices, rigidity cutoffs, and nucleon fractions are compared to recent Auger results. The FR0 simulations
include the approximately isotropic distribution of FR0 galaxies and various intergalactic
magnetic field configurations (including random and structured fields) and predict the fluxes of
secondary photons and neutrinos produced during UHECR propagation through cosmic photon
backgrounds. This comprehensive simulation allows for investigating the properties of the FR0
sources using observational multi-messenger data.
Keywords: ultra-high energy cosmic rays, UHECR propagation, CRPropa, active galactic nuclei, jetted AGN, FR0 radio galaxies, Pierre Auger Observatory, UHECR energy spectrum
Published in RUNG: 24.08.2023; Views: 1984; Downloads: 5
Full text (1,12 MB)
This document has many files! More... |
