CRPropa face-to-face meeting

30 Sept 2019, 09:00 → 2 Oct 2019, 18:00 Europe/Berlin

SR1 (DESY, Zeuthen)

CRPropa face-to-face meeting

This meeting will focus on simulations of astroparticle physics from TeV - ZeV energies with CRPropa (see crpropa.desy.de). We will meet for three days at DESY, Zeuthen to discuss recent developments in the CRPropa framework, physics applications of CRPropa and, more generally, topics related to simulations of astroparticle physics. If you are a developer or user of CRPropa, or if you are just interested in the general topic of simulations in astroparticle physics in the TeV - ZeV energy range, you are encouraged to join us in Zeuthen from September 30^th until October 2^nd.

 

Important dates

• Registration deadline: 16/09/2019
• Abstract submission deadline: 16/09/2019
• Meeting: 30/09/2019 - 02/10/2019

 

Location

DESY, Zeuthen
Platanenallee 6, 15738 Zeuthen
Room: SR1

 

Travel / Accommodation / Meeting Fee

For information on how to reach the workshop, on possible accommodation options, on the meeting fee and on dinner/lunch/coffee breaks, see the 'Useful Information' tab.

 

PAHEN 2019

Right before this meeting, from September 25^th to 27^th, the 'PAHEN 2019' conference will be held in Berlin. This conference will focus on 'Perspectives in Astroparticle physics from High Energy Neutrinos'. Participants of the CRPropa meeting who are interested in this topic are encouraged to join this conference as well. For registration, see https://indico.desy.de/indico/event/22051/.

 

Don't hesitate to contact the local organizers if you have any questions.

Monday 30 September

09:00 → 09:30 Registration

09:30 → 10:30 Presentations 1

Convener: Dr Arjen van Vliet (DESY Zeuthen)

09:30 Welcome

Welcome

Speaker: Dr Arjen van Vliet (DESY Zeuthen)

Slides Welcome.pdf

09:45 Turbulence modeling with CRPropa - summary of recent results

In this talk, I will give an overview of last year's activities of the group in Bochum concerning the modeling of cosmic ray propagation in turbulent magnetic fields with CRPropa. Two central projects will be the focus of this work: (1) investigations of different interpolation routines and their influence on the physics results; (2) the connection between the wave vector spectrum and the energy dependence of the diffusion tensor in the context of Galactic cosmic-ray propagation.

Speaker: Prof. Julia Tjus (Ruhr-Universität Bochum)

Slides Turbulence_Bochum_Final_pdf.pdf

10:30 → 11:00 Coffee break

11:00 → 12:30 Presentations 2

Convener: Dr Andrej Dundovic (Gran Sasso Science Institute L'Aquila)

11:00 Local Source Simulations in CRPropa - Status & Applications

CRPropa itself is written to suit astrophysical simulations across (extra-) galactic distances, yet already features many aspects necessary to simulate phenomena inside the sources of cosmic rays themselves. I shall present an extended version of CRPropa applicable on (yet not constrained to) sub-kpc-scales making use of customizable photon fields, hadron-hadron interactions, as well as fully customizable space- and time dependence in all of CRPropa's interaction modules and background fields. These abilities allow for CRPropa to enter previously inaccessible realms of astrophysics which I wish to illustrate at the example of physics in jets of active galactic nuclei.

Speaker: Mr Mario Hörbe (Ruhr-Uni Bochum & University of Oxford)

Slides Mario_Hoerbe.pdf

11:30 Improving photomeson interactions of cosmic-ray nuclei: shadowing, pion-reduction and nuclear breakup

Improving photomeson interactions of cosmic-ray nuclei: shadowing, pion-reduction and nuclear breakup

Speaker: Mr Leonel Morejon (DESY, Zeuthen)

Slides CRPropaMeeting2019.pdf

12:00 First (and second) order Fermi acceleration in CRPropa

First (and second) order Fermi acceleration in CRPropa

Speaker: Dr Jörg Paul Rachen (Vrije Universiteit Brussel)

12:30 → 13:30 Lunch break

13:30 → 14:00 Presentations 3

Convener: Dr Rafael Alves Batista (Radboud University)

13:30 UHECRs with CRPropa: understanding the effects of astrophysical hypothesis and source distance

UHECRs with CRPropa: understanding the effects of astrophysical hypothesis and source distance

Speaker: Mr Rodrigo Guedes Lang (IFSC-USP & DESY)

Slides Lang_CRPropaMeeting.pdf

14:00 → 15:30 Discussions 1

Convener: Dr Rafael Alves Batista (Radboud University)

15:30 → 16:00 Coffee break

16:00 → 18:00 Discussions 2

Convener: Dr Rafael Alves Batista (Radboud University)

18:30 → 21:30 Dinner

Tuesday 1 October

09:00 → 10:30 Presentations 4

Convener: Dr Andrej Dundovic (Gran Sasso Science Institute L'Aquila)

09:00 Simulation of formation and propagation of cosmic-ray ensembles

High energy particles, including photons, should interact with matter and various types of radiation while propagating through the Universe. These interactions obviously initiate particle cascades of various types and sizes, here referred to as cosmic-ray ensembles (CRE). Some preliminary results of the study of conditions under which it will be possible to identify at least two cosmic ray belonging to one CRE at the Earth are presented and discussed.

Speaker: Mr Oleksandr Sushchov (Institute of Nuclear Physics Polish Academy of Science)

Slides sushchov_crpropa_2019.pdf

09:30 The Impact of Plasma Instabilities on the Spectra of TeV Blazars

Relativistic jets from blazars are known to be sources of very-high-energy gamma rays (VHEGRs). During their propagation in the intergalactic space, VHEGRs interact with pervasive cosmological photon fields such as the extragalactic background light (EBL) and the cosmic microwave background (CMB), producing electron-positron pairs. These pairs can upscatter CMB/EBL photons to high energies via inverse Compton scattering, thereby continuing the cascade process. This is often used to set limits on intergalactic magnetic fields (IGMFs). However, the picture may change if plasma instabilities, arising due to the interaction of the pairs with the intergalactic medium (IGM), cool down the electrons/positrons faster than inverse Compton scattering. As a consequence, the kinetic energy lost by the pairs to the IGM could cause a hardening in the observed gamma-ray spectrum at energies below ∼100 GeV. Here, we study several types and models of instabilities and assess their impact for interpreting observations of distant blazars by using an extension for CRPropa which takes into account these energy losses. Our results suggest that plasma instabilities can describe the spectra of some blazars and mimic the effects of IGMFs, depending on parameters such as the intrinsic spectrum of the object, the density and temperature of the IGM, and the luminosity of the beam. On the other hand, we find that for our fiducial set of parameters plasma instabilities do not have a major impact on the spectra of some of the blazars studied. Therefore, they may be used for constraining IGMFs.

Speaker: Dr Andrey Saveliev (Immanuel Kant Baltic Federal University)

Slides Saveliev_CRPropa2019.pdf

10:00 A look into Sgr A*: gamma-ray and neutrino emissions

A look into Sgr A*: gamma-ray and neutrino emissions

Speaker: Dr Rafael Alves Batista (Radboud University)

Slides rab-crpropa-2019-sgra.pdf

10:30 → 11:00 Coffee break

11:00 → 12:30 Presentations 5

Convener: Dr Andrey Saveliev (Immanuel Kant Baltic Federal University)

11:00 CRPropa and cosmic ray transport in turbulent magnetic fields

Cosmic magnetic fields, both in the galaxy and in intergalactic space, can significantly influence the propagation of cosmic rays. What can be inferred from theoretical reasoning and observations is that those magnetic fields are highly turbulent. Yet, understanding theoretically hydrodynamic turbulence is an everlasting goal of classical physics, while the subject of magnetohydrodynamic (MHD) turbulence, omnipresent in the realm of astrophysics, is even more complex and challenging to study. Hence, investigating effects of the cosmic ray propagation in a turbulent MHD medium can shed some light both on the problem of turbulence itself, and the theory of cosmic ray transport. Here, we present a broad study of cosmic ray transport in so-called synthetic models of turbulence, results obtained, and challenges encountered. The numerical part of the work has been performed with CRPropa 3.

Speaker: Dr Andrej Dundovic (Gran Sasso Science Institute L'Aquila)

Slides AndrejDundovic-crpropa-2019-slides.pdf

11:30 Propagation of UHECRs in helical magnetic fields

Propagation of UHECRs in helical magnetic fields

Speaker: Dr Rafael Alves Batista (Radboud University)

Slides rab-crpropa-2019-helicity.pdf

12:00 Investigating the GMF; including CRPropa in IMAGINE

Investigating the GMF; including CRPropa in IMAGINE

Speaker: Mr Stefan Hackstein (Hamburger Sternwarte)

Slides Hackstein_IMAGINE_CRPropa.pdf

12:30 → 13:30 Lunch break

13:30 → 14:00 Presentations 6

Convener: Dr Tobias Winchen

13:30 Implementation of the targeting algorithm

Implementation of the targeting algorithm

Speaker: Dr Jörg Paul Rachen (Astrophysical Institute, Vrije Universiteit Brussel)

Slides VanVliet_TargetingPoster_ICRC2019.pdf

14:00 → 15:30 Discussions 3

Convener: Dr Tobias Winchen

15:30 → 16:00 Coffee break

16:00 → 18:00 Discussions 4

Convener: Dr Tobias Winchen

18:30 → 21:30 Dinner

Wednesday 2 October

09:00 → 10:30 Presentations 7

Convener: Dr Rafael Alves Batista (Radboud University)

09:00 On the impact of different nuclear disintegration and air-shower models on fitting the UHECR spectrum and composition

On the impact of different nuclear disintegration and air-shower models on fitting the UHECR spectrum and composition

Speaker: Mr Jonas Heinze (Desy Zeuthen)

Slides 2019_10_01_Heinze_CRPropa_f2f_UHECR.pdf

09:30 A parametrized catalog of radio galaxies as UHECR sources

A parametrized catalog of radio galaxies as UHECR sources

Speaker: Dr Jörg Paul Rachen (Vrije Universiteit Brussel)

Slides Rachen_RG_Catalog_talk.pdf

10:00 Ultra high energy cosmic rays from very high gamma ray sources

Ultra high energy cosmic rays from very high gamma ray sources

Speaker: Ms Rahima Doghmane (Badji Mokhtar University)

Slides Presentation.pdf

10:30 → 11:00 Coffee break

11:00 → 12:30 Presentations 8

Convener: Dr Arjen van Vliet (DESY Zeuthen)

11:00 Comparison between Cash-Karp (CK) and Boris Push (BP) for propagating particles in CRPropa

Numerical simulations of the propagation of charged particles through magnetic fields, solving the equation of motion can be achieved in principle with many different algorithms. There are, however, an increasing number of studies that have found that there are two algorithms, which work in general best for propagating charged particles within a magnetic field. These two algorithms, namely the Cash-Karp (CK) and the Boris Push (BP), are now implemented in CRPropa. Both are compared and evaluated within this presentation. It is demonstrated that the Boris Push provides a faster method for advancing charged particles within a magnetic field while it even preserves the components of the momentum.

Speaker: Mr Patrick Reichherzer (Ruhr-Universität Bochum)

Slides BP_-_CK_Patrick_Reichherzer_10.2019.pdf

11:30 Observer sphere lensing

For Galactic propagation studies with forward-tracking, a choice between realism (lack of artefacts in the arrival direction distribution from finite observer sizes) and statistics must be made. An approach to overcome this dilemma called *observer sphere lensing*, that utilises the known Galactic lensing approach for small volumes in the vicinity of Earth, will be introduced. Results from preliminary studies comparing the improvement of the arrival direction distribution when employing this method will be presented and its applicability for different cases will be discussed.

Speaker: Mr Alex Kääpä (Bergische Universität Wuppertal)

Slides presentationPre.pdf

12:00 Progress on the momentum diffusion module

Progress on the momentum diffusion module

Speaker: Mr Lukas Merten (Ruhr-Universität Bochum)

Slides Merten_CRPropa_2019.pdf

12:30 → 13:30 Lunch break

13:30 → 15:30 Parallel optional discussions 1

15:30 → 16:00 Coffee break

16:00 → 18:00 Parallel optional discussions 2