Magnetic diffusion effects on the Ultra-High Energy Cosmic Ray spectrum and composition

Autores
Mollerach, Maria Silvia; Roulet, Esteban
Año de publicación
2013
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
We discuss the effects of diffusion of high energy cosmic rays in turbulent extra-galactic magnetic fields. We find an approximate expression for the low energy suppression of the spectrum of the different mass components (with charge Z) in the case in which this suppression happens at energies below ∼ Z EeV, so that energy losses are dominated by the adiabatic ones. The low energy suppression appears when cosmic rays from the closest sources take a time comparable to the age of the Universe to reach the Earth. This occurs for energies E < Z EeV (B/nG)p lc/Mpc(ds/70 Mpc) in terms of the magnetic field RMS strength B, its coherence length lc and the typical separation between sources ds. We apply this to scenarios in which the sources produce a mixed composition and have a relatively low maximum rigidity (Emax ∼ (2–10)Z EeV), finding that diffusion has a significant effect on the resulting spectrum, the average mass and on its spread, in particular reducing this last one. For reasonable values of B and lc these effects can help to reproduce the composition trends observed by the Auger Collaboration for source spectra compatible with Fermi acceleration.
Fil: Mollerach, Maria Silvia. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Fil: Roulet, Esteban. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Materia
Ultra High Energy Cosmic Rays
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/17637
Acceder
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network_name_str CONICET Digital (CONICET)
spelling Magnetic diffusion effects on the Ultra-High Energy Cosmic Ray spectrum and compositionMollerach, Maria SilviaRoulet, EstebanUltra High Energy Cosmic Rayshttps://purl.org/becyt/ford/1.3https://purl.org/becyt/ford/1We discuss the effects of diffusion of high energy cosmic rays in turbulent extra-galactic magnetic fields. We find an approximate expression for the low energy suppression of the spectrum of the different mass components (with charge Z) in the case in which this suppression happens at energies below ∼ Z EeV, so that energy losses are dominated by the adiabatic ones. The low energy suppression appears when cosmic rays from the closest sources take a time comparable to the age of the Universe to reach the Earth. This occurs for energies E < Z EeV (B/nG)p lc/Mpc(ds/70 Mpc) in terms of the magnetic field RMS strength B, its coherence length lc and the typical separation between sources ds. We apply this to scenarios in which the sources produce a mixed composition and have a relatively low maximum rigidity (Emax ∼ (2–10)Z EeV), finding that diffusion has a significant effect on the resulting spectrum, the average mass and on its spread, in particular reducing this last one. For reasonable values of B and lc these effects can help to reproduce the composition trends observed by the Auger Collaboration for source spectra compatible with Fermi acceleration.Fil: Mollerach, Maria Silvia. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Roulet, Esteban. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaIop Publishing2013-09info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/17637Mollerach, Maria Silvia; Roulet, Esteban; Magnetic diffusion effects on the Ultra-High Energy Cosmic Ray spectrum and composition; Iop Publishing; Journal Of Cosmology And Astroparticle Physics; 2013; 9-2013; 1-161475-7516enginfo:eu-repo/semantics/altIdentifier/doi/10.1088/1475-7516/2013/10/013info:eu-repo/semantics/altIdentifier/url/http://iopscience.iop.org/article/10.1088/1475-7516/2013/10/013/metainfo:eu-repo/semantics/altIdentifier/url/https://arxiv.org/abs/1305.6519info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-03T09:51:43Zoai:ri.conicet.gov.ar:11336/17637instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-09-03 09:51:43.919CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Magnetic diffusion effects on the Ultra-High Energy Cosmic Ray spectrum and composition
title Magnetic diffusion effects on the Ultra-High Energy Cosmic Ray spectrum and composition
spellingShingle Magnetic diffusion effects on the Ultra-High Energy Cosmic Ray spectrum and composition
Mollerach, Maria Silvia
Ultra High Energy Cosmic Rays
title_short Magnetic diffusion effects on the Ultra-High Energy Cosmic Ray spectrum and composition
title_full Magnetic diffusion effects on the Ultra-High Energy Cosmic Ray spectrum and composition
title_fullStr Magnetic diffusion effects on the Ultra-High Energy Cosmic Ray spectrum and composition
title_full_unstemmed Magnetic diffusion effects on the Ultra-High Energy Cosmic Ray spectrum and composition
title_sort Magnetic diffusion effects on the Ultra-High Energy Cosmic Ray spectrum and composition
dc.creator.none.fl_str_mv Mollerach, Maria Silvia
Roulet, Esteban
author Mollerach, Maria Silvia
author_facet Mollerach, Maria Silvia
Roulet, Esteban
author_role author
author2 Roulet, Esteban
author2_role author
dc.subject.none.fl_str_mv Ultra High Energy Cosmic Rays
topic Ultra High Energy Cosmic Rays
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv We discuss the effects of diffusion of high energy cosmic rays in turbulent extra-galactic magnetic fields. We find an approximate expression for the low energy suppression of the spectrum of the different mass components (with charge Z) in the case in which this suppression happens at energies below ∼ Z EeV, so that energy losses are dominated by the adiabatic ones. The low energy suppression appears when cosmic rays from the closest sources take a time comparable to the age of the Universe to reach the Earth. This occurs for energies E < Z EeV (B/nG)p lc/Mpc(ds/70 Mpc) in terms of the magnetic field RMS strength B, its coherence length lc and the typical separation between sources ds. We apply this to scenarios in which the sources produce a mixed composition and have a relatively low maximum rigidity (Emax ∼ (2–10)Z EeV), finding that diffusion has a significant effect on the resulting spectrum, the average mass and on its spread, in particular reducing this last one. For reasonable values of B and lc these effects can help to reproduce the composition trends observed by the Auger Collaboration for source spectra compatible with Fermi acceleration.
Fil: Mollerach, Maria Silvia. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Fil: Roulet, Esteban. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
description We discuss the effects of diffusion of high energy cosmic rays in turbulent extra-galactic magnetic fields. We find an approximate expression for the low energy suppression of the spectrum of the different mass components (with charge Z) in the case in which this suppression happens at energies below ∼ Z EeV, so that energy losses are dominated by the adiabatic ones. The low energy suppression appears when cosmic rays from the closest sources take a time comparable to the age of the Universe to reach the Earth. This occurs for energies E < Z EeV (B/nG)p lc/Mpc(ds/70 Mpc) in terms of the magnetic field RMS strength B, its coherence length lc and the typical separation between sources ds. We apply this to scenarios in which the sources produce a mixed composition and have a relatively low maximum rigidity (Emax ∼ (2–10)Z EeV), finding that diffusion has a significant effect on the resulting spectrum, the average mass and on its spread, in particular reducing this last one. For reasonable values of B and lc these effects can help to reproduce the composition trends observed by the Auger Collaboration for source spectra compatible with Fermi acceleration.
publishDate 2013
dc.date.none.fl_str_mv 2013-09
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/11336/17637
Mollerach, Maria Silvia; Roulet, Esteban; Magnetic diffusion effects on the Ultra-High Energy Cosmic Ray spectrum and composition; Iop Publishing; Journal Of Cosmology And Astroparticle Physics; 2013; 9-2013; 1-16
1475-7516
url http://hdl.handle.net/11336/17637
identifier_str_mv Mollerach, Maria Silvia; Roulet, Esteban; Magnetic diffusion effects on the Ultra-High Energy Cosmic Ray spectrum and composition; Iop Publishing; Journal Of Cosmology And Astroparticle Physics; 2013; 9-2013; 1-16
1475-7516
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/doi/10.1088/1475-7516/2013/10/013
info:eu-repo/semantics/altIdentifier/url/http://iopscience.iop.org/article/10.1088/1475-7516/2013/10/013/meta
info:eu-repo/semantics/altIdentifier/url/https://arxiv.org/abs/1305.6519
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
dc.publisher.none.fl_str_mv Iop Publishing
publisher.none.fl_str_mv Iop Publishing
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
collection CONICET Digital (CONICET)
instname_str Consejo Nacional de Investigaciones Científicas y Técnicas
repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
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score 13.13397

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