Arjen van Vliet

CRPropa 2.0 -- a Public Framework for Propagating High Energy Nuclei, Secondary Gamma Rays and Neutrinos

Version 2.0 of CRPropa 1 is public software to model the extra-galactic propagation of ultra-high energy nuclei of atomic number Z 26 through structured magnetic fields and ambient photon backgrounds taking into account all relevant particle interactions. CRPropa covers the energy range 6 10 16 < E=eV < A 10 22 where A is the nuclear mass number. CRPropa can also be used to track secondary -rays and neutrinos which allows the study of their link with the charged primary nuclei ‐ the so called multi-messenger connection. After a general introduction we present several sample applications of current interest concerning the physics of extragalactic ultra-high energy radiation.

PeV neutrinos from the propagation of ultra-high energy cosmic rays

We discuss the possibility that the PeV neutrinos recently observed by IceCube are produced by the interactions of extragalactic cosmic rays during their propagation through the radiation backgrounds. We show that the fluxes resulting from the decays of neutrons produced in the interactions of cosmic ray protons with the CMB background are suppressed (E 2 d��/dE < 10 −10 GeV/cm 2 s sr), with those resulting from the decays of pions produced in the interactions with the UV/optical/IR backgrounds being the dominant ones at PeV energies. The anti-neutrino fluxes produced by the decay of neutrons resulting from the photodisintegration of heavy nuclei with CMB photons are also shown to be quite suppressed (E 2 � d��/dE < 10 −11 GeV/cm 2 s sr), while those produced by photo-pion processes with UV/optical/IR backgrounds may be larger, although they are not expected to be above those achievable in the pure proton case. Scenarios with mixed composition and low cutoff rigidities can lead to PeV neutrino fluxes enhanced with respect to those in the pure Fe scenarios. We also discuss the possible impact of the Glashow resonance for the detection of these scenarios, showing that it plays a moderate role.

CRPropa 3-a public astrophysical simulation framework for propagating extraterrestrial ultra-high energy particles

We present the simulation framework CRPropa version 3 designed for efficient development of astrophysical predictions for ultra-high energy particles. Users can assemble modules of the most relevant propagation effects in galactic and extragalactic space, include their own physics modules with new features, and receive on output primary and secondary cosmic messengers including nuclei, neutrinos and photons. In extension to the propagation physics contained in a previous CRPropa version, the new version facilitates high-performance computing and comprises new physical features such as an interface for galactic propagation using lensing techniques, an improved photonuclear interaction calculation, and propagation in time dependent environments to take into account cosmic evolution effects in anisotropy studies and variable sources. First applications using highlighted features are presented as well.

Cosmogenic gamma-rays and neutrinos constrain UHECR source models

We use CRPropa 3 to show how the expected cosmogenic neutrino and gamma-ray spectra depend on the maximum energy of ultra-high energy cosmic rays (UHECRs) at their sources, on the spectral index at injection and on the chemical composition of UHECRs. The isotropic diffuse gamma-ray background measured by Fermi/LAT is already close to touching upon a model with co-moving source evolution and with the chemical composition, spectral index and maximum acceleration energy optimized to provide the best fit to the UHECR spectrum and composition measured by the Pierre Auger Collaboration. Additionally, the detectable fraction of protons present at the highest energies in UHECRs, for experiments with sensitivities to the single-flavor neutrino flux at

CRPropa 3.0 – a Public Framework for Propagating UHE Cosmic Rays through Galactic and Extragalactic Space

\sim1

PeV Neutrinos from Ultra-High-Energy Cosmic Rays

EeV in the range of

Public Software to Model Extragalactic Propagation of Ultra-High Energy Nuclei

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CRPropa 2.0 - Public Software to Model Extragalactic Propagation of Ultra-High Energy Nuclei

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