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. CRPropa features a very flexible simulation setup with 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. Please consider using the master branch directly.

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.

To receive announcements etc., please subscribe to our mailing list by sending a mail with subject: subscribe crpropa-user to from the address you wish to subscribe.

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.
  • Data for the constrained 'Hackstein' models of the local Universe using initial conditions from the CLUES project can be downloaded here. Instruction on how to use them can be found on the examples page.

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 the following papers:

CRPropa Component Reference
photon production and electromagnetic cascade propagation Astropart. Phys. 102 (2018) 39; arXiv:1710.11406
DiffusionSDE module JCAP 1706 (2017) 046; arXiv:1704.07484
turbulent magnetic field witd helicity Phys. Rev. D94 (2016) 083005; arXiv:1607.00320
multi-resolution implementation of magnetic fields using Quimby JCAP 1608 (2016) 025; arXiv:1512.03172
magnetic lenses Astropart. Phys. 54 (2014) 110 arXiv:1302.3761

Data for several models are provided alongside CRPropa. Please cite the following references if you use one of the models in your simulation.

Model Reference
Galactic Magnetic Field
JF12 Astrophys. J. 757 (2012) 14; arXiv:1204.3662 and Astrophys. J. 761 (2012) L11; arXiv:1210.7820
Pshirkov Astrophys. J. 738 (2011) 192; arXiv:1103.0814
Extragalactic Magnetic Field
Dolag JCAP 01 (2005) 009; arXiv:astro-ph/0410419
Miniati Phys. Rev. D 70 (2004) 043007; arXiv:astro-ph/0401084
CLUES Mon. Not. Roy. Astron. Soc. 475 (2018) 2519 arXiv:1710.01353
Photon Backgrounds
Stecker16 Astrophys. J. 827 (2016) 6; arXiv:1605.01382
Gilmore12 Mon. Not. Roy. Astron. Soc. 422 (2012) 3189; arXiv:1104.0671
Dominguez11 Mon. Not. Roy. Astron. Soc. 410 (2011) 2556; arXiv:1007.1459
Finke10 Astrophys. J. 712 (2010) 238; arXiv:0905.1115
Franceschini08 Astron. Astrophys. 487 (2008) 837; arXiv:0805.1841
Stecker05 Astrophys. J. 648 (2006) 774; arXiv:astro-ph/0510449
Kneiske04 Astron. Astrophys. 413 (2004) 807; arXiv:astro-ph/0309141
Protheroe96 Astropart. Phys. 6 (1996) 45, Astropart. Phys. 7 (1997) 181; arXiv:astro-ph/9605119

Publications based on CRPropa

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