Impact of the magnetic horizon on the interpretation of the Pierre Auger Observatory spectrum and composition data

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378271%3A_____%2F24%3A00605641" target="_blank" >RIV/68378271:_____/24:00605641 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216208:11320/24:10493926 RIV/61989592:15310/24:73628478

Výsledek na webu

<a href="https://hdl.handle.net/11104/0363294" target="_blank" >https://hdl.handle.net/11104/0363294</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1088/1475-7516/2024/07/094" target="_blank" >10.1088/1475-7516/2024/07/094</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Impact of the magnetic horizon on the interpretation of the Pierre Auger Observatory spectrum and composition data

Popis výsledku v původním jazyce

The flux of ultra-high energy cosmic rays reaching Earth above the ankle energy (5 EeV) can be described as a mixture of nuclei injected by extragalactic sources with very hard spectra and a low rigidity cutoff. Extragalactic magnetic fields existing between the Earth and the closest sources can affect the observed CR spectrum by reducing the flux of low-rigidity particles reaching Earth. We perform a combined fit of the spectrum and distributions of depth of shower maximum measured with the Pierre Auger Observatory including the effect of this magnetic horizon in the propagation of UHECRs in the intergalactic space. We find that, within a specific range of the various experimental and phenomenological systematics, the magnetic horizon effect can be relevant for turbulent magnetic field strengths in the local neighbourhood in which the closest sources lie of order B-rms similar or equal to (50-100) nG(20Mpc/ds)(100 kpc/L-coh)(1/2), with d(s) the typical intersource separation and L-coh the magnetic field coherence length. When this is the case, the inferred slope of the source spectrum becomes softer and can be closer to the expectations of diffusive shock acceleration, i.e., proportional to E-2. An additional cosmic-ray population with higher source density and softer spectra, presumably also extragalactic and dominating the cosmic-ray flux at EeV energies, is also required to reproduce the overall spectrum and composition results for all energies down to 0.6 EeV.

Název v anglickém jazyce

Impact of the magnetic horizon on the interpretation of the Pierre Auger Observatory spectrum and composition data

Popis výsledku anglicky

The flux of ultra-high energy cosmic rays reaching Earth above the ankle energy (5 EeV) can be described as a mixture of nuclei injected by extragalactic sources with very hard spectra and a low rigidity cutoff. Extragalactic magnetic fields existing between the Earth and the closest sources can affect the observed CR spectrum by reducing the flux of low-rigidity particles reaching Earth. We perform a combined fit of the spectrum and distributions of depth of shower maximum measured with the Pierre Auger Observatory including the effect of this magnetic horizon in the propagation of UHECRs in the intergalactic space. We find that, within a specific range of the various experimental and phenomenological systematics, the magnetic horizon effect can be relevant for turbulent magnetic field strengths in the local neighbourhood in which the closest sources lie of order B-rms similar or equal to (50-100) nG(20Mpc/ds)(100 kpc/L-coh)(1/2), with d(s) the typical intersource separation and L-coh the magnetic field coherence length. When this is the case, the inferred slope of the source spectrum becomes softer and can be closer to the expectations of diffusive shock acceleration, i.e., proportional to E-2. An additional cosmic-ray population with higher source density and softer spectra, presumably also extragalactic and dominating the cosmic-ray flux at EeV energies, is also required to reproduce the overall spectrum and composition results for all energies down to 0.6 EeV.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10303 - Particles and field physics

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2024

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Cosmology and Astroparticle Physics

ISSN

1475-7516

e-ISSN

1475-7516

Svazek periodika

2024

Číslo periodika v rámci svazku

7

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

31

Strana od-do

094

Kód UT WoS článku

001371213400001

EID výsledku v databázi Scopus

2-s2.0-85200904195