Report/Journal Article

PUBDB-2017-10998

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Probing Intergalactic Magnetic Fields with Simulations of Electromagnetic Cascades

Alves Batista, R.Extern* ; Saveliev, A.Extern* ; Sigl, G. (Corresponding author)Extern* ; Vachaspati, T. (Corresponding author)

2016
APS Woodbury, NY

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Please use a persistent id in citations: doi:10.1103/PhysRevD.94.083005  doi:10.3204/PUBDB-2017-10998

Report No.: DESY-16-196; arXiv:1607.00320

Abstract: We determine the effect of intergalactic magnetic fields on the distribution of high-energy gamma rays by performing three-dimensional Monte Carlo simulations of the development of gamma-ray-induced electromagnetic cascades in the magnetized intergalactic medium. We employ the so-called “Large Sphere Observer” method to efficiently simulate blazar gamma ray halos. We study magnetic fields with a Batchelor spectrum and with maximal left- and right-handed helicities. We also consider the case of sources whose jets are tilted with respect to the line of sight. We verify the formation of extended gamma ray halos around the source direction, and observe spiral-like patterns if the magnetic field is helical. We apply the Q-statistics to the simulated halos to extract their spiral nature and also propose an alternative method, the S-statistics. Both methods provide a quantitative way to infer the helicity of the intervening magnetic fields from the morphology of individual blazar halos for magnetic field strengths B≳10-15 G and magnetic coherence lengths Lc≳100 Mpc. We show that the S-statistics has a better performance than the Q-statistics when assessing magnetic helicity from the simulated halos.

Keyword(s): gamma ray: halo ; cascade: electromagnetic ; helicity: magnetic ; gamma ray: energy ; coherence: length ; energy: high ; numerical calculations: Monte Carlo ; dimension: 3 ; magnetic field ; blazar ; field strength ; right-handed ; performance ; formation ; sphere

Note: 14 pages, 7 figures

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Contributing Institute(s):

1. Uni Hamburg / Theorie (UNI/TH)

Research Program(s):

1. 611 - Fundamental Particles and Forces (POF3-611) (POF3-611)

Experiment(s):

1. No specific instrument

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Database coverage:
; ; ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; IF < 5 ; JCR ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

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