Case for Centaurus A as the main source of ultrahigh-energy cosmic rays

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378271%3A90232%2F24%3A00641989" target="_blank" >RIV/68378271:90232/24:00641989 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.1103/PhysRevD.110.063030" target="_blank" >https://doi.org/10.1103/PhysRevD.110.063030</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/PhysRevD.110.063030" target="_blank" >10.1103/PhysRevD.110.063030</a>

Result language

angličtina

Original language name

Case for Centaurus A as the main source of ultrahigh-energy cosmic rays

Original language description

We discuss the possibility that a dominant fraction of the cosmic rays above the ankle (i.e., above 5 EeV) is due to a single nearby source, considering in particular the radio galaxy Centaurus A. We focus on the properties of the source spectrum and composition required to reproduce the observations, showing that the nuclei are strongly suppressed for E>10Z EeV, either by a rigidity dependent source cutoff or by the photodisintegration interactions with the cosmic microwave background at the giant dipole resonance. The very mild attenuation effects at lower energies imply that the secondary nuclei from this source, produced in photodisintegration processes during propagation, only provide a small contribution. Given the moderate anisotropies observed, the deflections in extragalactic and Galactic magnetic fields should play a crucial role in determining the cosmic ray arrival direction distribution. The diffusion in extragalactic fields as well as the finite source lifetime also significantly affect the shape of the observed spectrum. The cosmic ray flux at tens of EeV is dominated by the CNO component, and we show that it is actually better reproduced by a mixture of C and O nuclei rather than by the usual assumption of a N component effectively describing this mass group. The Si and Fe group components become dominant above 70 EeV, in the energy range in which a strong spectral suppression is present. If the localized flux excess appearing above 40 EeV around the Centaurus A direction is attributed to the CNO component, the He nuclei from the source in the energy range from 10 to 20 EeV could lead to a similar anisotropy unless its contribution is suppressed. The cosmic ray flux at a few EeV should mostly result from a more isotropic light component associated to a population of extragalactic sources. The inclusion of the subdominant contribution of heavy nuclei from the Galactic component helps to reproduce the observations around 1 EeV.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10303 - Particles and field physics

Project

—

Continuities

—

Publication year

2024

Confidentiality

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

Name of the periodical

Physical Review D

ISSN

2470-0010

e-ISSN

2470-0029

Volume of the periodical

110

Issue of the periodical within the volume

6

Country of publishing house

US - UNITED STATES

Number of pages

22

Pages from-to

063030

UT code for WoS article

001317463100003

EID of the result in the Scopus database

2-s2.0-85204437090