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

CRPropa - The Official Website

CRPropa3 - Overview

CRPropa is a publicly available simulation framework to study the propagation of ultra-high-energy nuclei up to iron on their voyage through an (extra)galactic environment. It takes into account: pion production, photodisintegration and energy losses by pair production of all relevant isotopes in the ambient low-energy photon fields as well as nuclear decay. CRPropa can model the deflection in (inter)galactic magnetic fields, the propagation of secondary electromagnetic cascades and neutrinos for a multitude of scenarios for different source distributions and magnetic environments. It enables the user to predict the spectra of UHECR (and of their secondaries), their composition and arrival direction distribution. Additionally, the low-energy Galactic propagation can be simulated by solving the transport equation using stochastic differential equations.

This is the current version of CRPropa. It features a very flexible simulation setup, support for specialized extragalactic magnetic fields, galactic propagation and galactic lensing, python steering and shared-memory parallelization.

Try it out

You can try out CRPropa online at
Use the guest login and go to the CRPropa example via "VISPA Cluster" --> "Open Examples".

Installation, getting started and documentation

You can download the code from our github page. Note that the major releases are infrequent and may not contain latest features and bug fixes found in the master branch of the repository.

Installation instructions and user manuals are found on the wiki page. To get started we suggest to look at the tutorials and examples. For detailed documentation of the code see the Doxygen documentation


Please use the ticket system for support and in case of general questions. Please browse the wiki and previous support requests on installation and usage of CRPropa before opening a new ticket.

Additional resources

  • The galactic magnetic field lenses can be downloaded here and instruction on how to use them can be found on the examples page.
  • The multi-resolution 'Dolag' extragalactic magnetic field, using Quimby, can be downloaded here
  • The 'Miniati', 'Dolag' and 'Benchmark' extragalactic magnetic field models on regular grids are available here and the corresponding large-scale structure density fields can be downloaded here. Instructions on how to use them will be added to the examples page soon.

Publications based on CRPropa

An extensive list of publications using CRPropa can be found via inSPIRE.

How to cite CRPropa

If you use CRPropa 3 for your research, please cite:

JCAP 1605 (2016) 038; arXiv:1603.07142

In addition, depending on the features you use, please cite

  • for photon production and electromagnetic cascade propagation: arXiv:1710.11406
  • for the DiffusionSDE module: JCAP 1706 (2017) 046; arXiv:1704.07484
  • for the turbulent magnetic field with helicity: Phys. Rev. D94 (2016) 083005; arXiv:1607.00320
  • for the multi-resolution implementation of magnetic fields using Quimby: JCAP 1608 (2016) 025; arXiv:1512.03172
  • and for the magnetic lenses: Astropart. Phys. 54 (2014) 110 arXiv:1302.3761

Or, if you use any of these magnetic field or extragalactic background light models, please cite

  • for the JF12 galactic magnetic field: Astrophys. J. 757 (2012) 14; arXiv:1204.3662 and Astrophys. J. 761 (2012) L11; arXiv:1210.7820
  • for the Pshirkov galactic magnetic field: Astrophys. J. 738 (2011) 192; arXiv:1103.0814
  • for the Dolag extragalactic magnetic field: JCAP 01 (2005) 009; arXiv:astro-ph/0410419
  • for the Miniati extragalactic magnetic field: Phys. Rev. D 70 (2004) 043007; arXiv:astro-ph/0401084
  • for the Stecker16 upper and lower extragalactic background lights: Astrophys. J. 827 (2016) 6; arXiv:1605.01382
  • for the Gilmore12 extragalactic background light: Mon. Not. Roy. Astron. Soc. 422 (2012) 3189; arXiv:1104.0671
  • for the Dominguez11 extragalactic background light: Mon. Not. Roy. Astron. Soc. 410 (2011) 2556; arXiv:1007.1459
  • for the Finke10 extragalactic background light: Astrophys. J. 712 (2010) 238; arXiv:0905.1115
  • for the Franceschini08 extragalactic background light: Astron. Astrophys. 487 (2008) 837; arXiv:0805.1841
  • for the Stecker05 extragalactic background light: Astrophys. J. 648 (2006) 774; arXiv:astro-ph/0510449
  • for the Kneiske04 extragalactic background light: Astron. Astrophys. 413 (2004) 807; arXiv:astro-ph/0309141
  • for the Protheroe96 extragalactic radio background: Astropart. Phys. 6 (1996) 45, Astropart. Phys. 7 (1997) 181; arXiv:astro-ph/9605119